Upgunning the Tarrasque

[Blackhawk748]

So, as we all know the Tarrasque isn't as impressive as its supposed to be, considering a single Allip can render it unconscious in short order. What I'd like to do is put the thing on the level of its lore; A massive civilzation destroying beast.

I'm just not sure how to do that.

So lets go over its problems and see what it needs.

1. Weak to Ability Drain
2. Ground bound and not terribly fast
3. Terrible feats
4. Lousy damage
5. Bad defenses (its AC is fine though and Carapace is pretty sweet)
6. No ability to deal with ranged

1. Ok, so the first is easy to fix, just add that particular immunity (which it should have had).

2. Next, I would say up its land speed to 60ft. It's got massive legs so this feels much better. A part of me wants to give it At-Will Dimension Door just to terrify PCs.

3. I... I don't even know what to do here. Even the arguably ok feats don't seem to have a purpose. This one needs a lot of work.

4. The feats should probably focus on boosting this section. Options here are a bit more limited. Making them count as magic is a good step to prevent incorporeal things from stopping it.

5. First step is to up its DR to 20 (yes DR doesn't do as much but combined with its regen this is preventing a lot of damage.) and the SR to at least 40, probably a bit higher. It also needs Blindsense to help it find stuff (or just get a higher Spot, that Spot is terrible)

6. Give it a breath weapon. This thing is basically DnD Godzilla so it may as well get a giant laser.

So there's my ideas, what have the rest of you got? Lets just keep this to something that would actually show up at the table.

[MaxiDuRaritry]

Give it the daikaiju template with no (or minimal) increase in CR.

Change its feats to give it a mix of ToB martial maneuvers and stances (along with a maneuver recovery mechanic of some sort), as well as some dabbling in incarnum.

Make it a true dragon, with all the benefits of the dragon type.

Give it true seeing and other special senses, full ranks in Perception skills (and perhaps a few other useful skills such as Use Rope), as well as the ability to bypass Darkstalker. Make its Int count as 10 for the purposes of gaining skill points.

Make it so when it periodically falls asleep, everyone forgets about it except very specific individuals of great power and insight, such as gods of knowledge, and they're unable to disseminate the information. No information is available, and Knowledge checks (and divinations) automatically fail against it for the purposes of its abilities in previous incarnations.

Seems like those would make the thing an absolutely terrifying opponent.

[Maat Mons]

Lack of Immunity to mind-affecting effects strikes me as the biggest oversight.

The +20 Will save it has isn't terrible. But you can get a DC of, what, 32 on Dominate Monster? That's a solid 60% chance of getting yourself a pet tarrasque.

[curious-puzzle]

I did have this version that I used for one of the final battles for my campaign:

Spoiler: The Beast

Show

Size/Type:
Colossal Evil Outsider
Hit Dice:
60d10+1020 (1620)
Initiative:
+8
Speed:
60 ft. (4 squares)
Armor Class:
43 (-8 size, +4 Dex, +37 natural), touch 5, flat-footed 43
Base Attack/Grapple:
+60/+81
Attack:
Bite +70 melee (4d8+17/18-20/×3)
Full Attack:
7 Bites +71 melee (4d8+18/18-20/×3) and 2 horns +65 melee (1d10+9) and 2 claws +65 melee (1d12+9) and tail slap +65 melee (3d8+9) and 4 tentacles +65 (3d6+9)
Space/Reach:
30 ft./20 ft. (30 ft with tentacles)
Special Attacks:
Augmented critical, frightful presence, improved grab, rush, swallow whole, Ruinous bellow, Really throw anything
Special Qualities:
Carapace, damage reduction 25/epic, immunity to fire, poison, disease, energy drain, ability damage and drain, resist acid and elec 10, regeneration 60, scent, spell resistance 36, uncanny dodge
Saves:
Fort +46, Ref +36, Will +41
Abilities:
Str 47, Dex 18, Con 44, Int 16, Wis 18, Cha 16
Skills:
Listen +25, Search +9, Spot +25, Survival +14 (+16 following tracks)
Feats:
Alertness, Knockback, Blind-Fight, Cleave, Combat Reflexes, Dodge, Great Cleave, Improved Bull Rush, Improved Initiative, Iron Will, Power Attack,Weapon focus Bite (bonus),Dire Charge, Endurance, Steadfast determination, Snatch, Improved snatch, Multisnatch, Large and in Charge, Stamp, Tail constrict,
Environment:
Any
Organization:
Solitary
Challenge Rating:
25 or 26 ish?
Treasure:
None
Alignment:
Always neutral
Advancement:
49+ HD (Colossal)
Level Adjustment:
—
Combat
The Beast attacks with its claws, teeth, horns, and tail.
The Beast’s natural weapons are treated as epic and magical weapons for the purpose of overcoming damage reduction and incorporeal miss chance.
Augmented Critical (Ex)
The Beast’s bite threatens a critical hit on a natural attack roll of 18-20, dealing triple damage on a successful critical hit.
Frightful Presence (Su)
The Beast can inspire terror by charging or attacking. Affected creatures must succeed on a DC 36 Will save or become shaken, remaining in that condition as long as they remain with 60 feet of the Beast. The save DC is Charisma-based.
Improved Grab (Ex)
To use this ability, the Beast must hit a Huge or smaller opponent with its bite or claw attack. It can then attempt to start a grapple as a free action without provoking an attack of opportunity. If it wins the grapple check, it establishes a hold and can try to swallow the foe the following round (if using the bite attack).
Rush (Ex)
Once per minute, the normally slow-moving Beast can move at a speed of 150 feet.
Swallow Whole (Ex)
The Beast can try to swallow a grabbed opponent of Huge or smaller size by making a successful grapple check. Once inside, the opponent takes 2d8+9 points of crushing damage plus 2d8+6 points of acid damage per round from the Beast’s digestive juices. A swallowed creature can cut its way out by dealing 50 points of damage to the Beast’s digestive tract (AC 25). Once the creature exits, muscular action closes the hole; another swallowed opponent must cut its own way out. The Beast’s gullet can hold 2 Huge, 8 Large, 32 Medium, 128 Small, or 512 Tiny or smaller creatures.
Carapace (Ex)
The Beast’s armorlike carapace is exceptionally tough and highly reflective, deflecting all rays, lines, cones, and even magic missile spells. There is a 30% chance of reflecting any such effect back at the caster; otherwise, it is merely negated. Check for reflection before rolling to overcome the creature’s spell resistance.
Regeneration (Ex)
No form of attack deals lethal damage to the Beast. The Beast regenerates even if it fails a saving throw against a disintegrate spell or a death effect. If the Beast fails its save against a spell or effect that would kill it instantly (such as those mentioned above), the spell or effect instead deals nonlethal damage equal to the creature’s full normal hit points +10. The Beast is immune to effects that produce incurable or bleeding wounds, such as mummy rot, a sword with the wounding special ability, or a clay golem’s cursed wound ability.
The Beast can be slain only by raising its nonlethal damage total to its full normal hit points +10 and using a wish or miracle spell to keep it dead.
If the Beast loses a limb or body part, the lost portion regrows in 1d6 minutes (the detached piece dies and decays normally). The creature can reattach the severed member instantly by holding it to the stump.

Ruinous bellow (Su)
The 7 maws of the Beast open wide to sing the song that ends the world. This bellow is powerful enough to shatter bones, crumble mountains, and tear at reality itself. Once every 1d4 rounds, the Beast can bellow as a free action, choosing either a burst or a cone. Every creature within 60 feet of the Beast (for a burst) or within a 120 ft cone (for the targeted cone) is subject to the following effects simultaneously (the save DC is 40 unless noted otherwise):

-The impact of the bellow generates a windstorm that scours the earth, hurling up clouds of dust as well as hapless victims. All affected must make a Fortitude save or be deafened permanently, are subject to Windstorm-level winds (as per the environmental effect, which may require a Fortitude save depending on creature size and location), and another Fortitude save or be knocked prone by the shockwave. If a creature fails against both the windstorm and the shockwave, treat them as one size category smaller than usual. If they would already be counted as Small or smaller before this reduction, double the distance they are blown back.

-The rocks and dust torn up by the bellow forms a thick cloud that remains for 4 rounds (60 ft radius and 60 ft high for the burst, and 120’ wide x 120’ for the cone). Anyone (except for the Beast) caught in the cloud is blinded while within and for 1 round after leaving (no save). Spellcasting is incredibly difficult in the dust cloud, requiring a concentration check of DC 40 for any spell with a vocal or somatic component. The cloud also provides concealment as per the spell fog cloud (blocks vision further than 5 ft, creatures within 5 feet have 20% concealment, further away has total concealment)

-Metal, stone, and flesh alike are shook apart and broken by the ruinous bellow. All creatures and objects within take 15d6 sonic damage (no save)

-If the sight of the Beast is not enough to crush hope, the sound of it is. All creatures within the bellow must make a Will save or be panicked for 2d6 rounds (shaken on a successful save). Once affected by the Beast's bellow, a creature is immune to being panicked or shaken by further bellows for 1 minute after they are no longer panicked or shaken (if they are subjected to another bellow while still under the effects of the previous one, the shaken/panicked effects do not stack)

-Not even magic is immune to the Beast’s titanic roar. If a creature rolls a critical failure (a nat 1) on any of the saving throws against the ruinous bellow, it is subjected to a targeted Greater Dispel magic (+20) as its enchantments are shattered. Any crystalline or glass items are affected as if hit with a shatter spell.

-Magical silence can afford some protection against the bellow, but only some. Any creature within a silence effect that is subject to the bellow takes half of the sonic damage, and receives a +8 on all other saving throws against the bellow. The silence spell is automatically dispelled and torn apart, however.

Really Throw Anything (EX):
As per the Hulking Hurler class feature, normally used with chunks of rock torn from the earth, nearby houses, anything unfortunate enough to be within reach of the Beast...

[zlefin]

feat-wise getting steadfast determination would be a good help for the tarrasque; better than iron will, even if you have to burn another feat on a prereq.

[Anthrowhale]

If you make it's attacks brilliant energy then it significantly increases damage via power attack. In general, if it could power attack for a full +48 the damage would be pretty scary.

[Sutr]

Option 1: have you considered making it an elder evil? The signs are good world enders?

Option 2: Tarrasque of legacy? Epic legacy should be in play. Gate and wish certainly help, but we may be able to use wish to change where it spent feats and skills. To me the Tarrasque having a +80 to disquise for a mundane disguise as a colossal scorpion. -20 for a different species, but it can be funny to have the pcs unable to identify it as it shows up in multiple encounters. It can fight in earnest later.

[Calthropstu]

Wasn't there a super tarrasque that rearranged the feats and added some templates posted a long time ago?

[Seerow]

Option 2: Tarrasque of legacy? Epic legacy should be in play. Gate and wish certainly help, but we may be able to use wish to change where it spent feats and skills. To me the Tarrasque having a +80 to disquise for a mundane disguise as a colossal scorpion. -20 for a different species, but it can be funny to have the pcs unable to identify it as it shows up in multiple encounters. It can fight in earnest later.

I love this.





My biggest suggestion would be giving the Tarrasque some aura that makes it outright immune to anything originating from more than say 30-50 feet away from it. If you try to fly outside its reach pinging it, you're not impacting it at all. If you can hurt it, it can hurt you back.

Honestly its numbers are scary enough where they are for the majority of characters, so from there other changes I would make include:
-Shore up weakness to Ability Drain and status effects. If you send in an Allip, it does nothing.

-Give it some ability to ignore high level defenses. Probably mindsight or true seeing to straight up ignore things like greater invis and mirror image. Give it the ability to roll multiple times against regular miss chance, taking the best result. Ideally find some way to deal with Immediate Action "take a bonus turn" effects that render its attacks useless.

-Make it more of a threat to surrounding areas. Its attacks deal multiplied damage against buildings. It can stomp/smash people, when attacking it hits a small aoe so it can crush armies quickly and efficiently, nullifying minionmancy effectiveness and also punish players for grouping up too closely.

-I don't actually like giving the Tarrasque maneuvers/stances, just for flavor reasons, but giving it some feats to take advantage of its combat reflexes would not go amiss. Hold the Line+Knockback to screw with chargers, Mage Slayer/Pierce Magical Concealment/Pierce Magical Protection is a good set of options as well (and better than what I suggested earlier with rolling twice on miss chance).

[Eldariel]

#1: Give Tarrasque Abomination-traits. Essentially it is one already so it should have them. This also gives it Divine Rank 0 by D&D, which gives it a neat array of extra stuff.

#2: Yeah, pick useful feats. Lethal charges, some ranged attacks (PF style Spine attack for instance or Destruction Rains from the Heavens á la Lavos from CT).

[Mato]

* Remove all toughness feats, give it one improved toughness feat.
It gains HP and has several open feats for customization this way.

* Remove awesome blow.
It sucks.

* Go ahead and remove cleave, great cleave, improved bullrush.
These feats are to make the Terrasqua terrifying to commoners. Each commoner killed gives it extra movement and an extra attack allowing it to rapidly kill low-hp opponents each round, destroying entire towns in mere seconds. But players are uninterested in this trait, it's useless against them, and as the DM you control pacing & placing anyway.

* Trade one of those feat slows for brutal throw.
It's attack bonus it also high enough to make anything into an improvised weapon.

* Trade four of those feat slots for an epic destiny.
Demigod gives it a divine rank value, greater restoration, and miracle covering it's weaknesses. Eternal Hero gives a Final Fantasy X Sin vibe as well as an extremely versatile 1/day ability. If nothing else body outside body creates 8 additional pseudo-terrasquas and is an excellent theatrical opening.

* Use 3~4 feat slots on martial study & martial stance.
Devoted spirit plays into the more divine/primordial nature, thicket of blades takes advantage of it's reach & combat reflexes and it can be combined with Robilar's gambit given it's considerable bite attack. Strike of righteous vitality allowing it to heal ability drain once per encounter as well. This also cycles back to the duplicates from eternal hero since they can use strikes to heal the original and increases the number of AoOs a creature will get hit by each round.

* Still wondering what to do? Planar Touchstone.
People have tried to shift it to other planes to get rid of it. But all that really did was give it a gallstone from eating the local touchstone site.
Player: "How did that terrasqua cast Fimbulwinter?"
DM: "It located an error in the Catalogues, twice, and someone it wished to be wiser hoping to give it an understanding of regret."
Player: "What errors could it have possibility found?"
DM: "That a terrasqua couldn't cast spells or beat the philosopher's challenge, turns out *chomp* is a perfectly acceptable answer to a terrasqua."

[Mr Adventurer]

We fought a Tarrasque that had the Half-Fiend template applied to it; that was pretty effective since all his Hit Dice really juiced up the template benefits.

[Blackhawk748]

Lack of Immunity to mind-affecting effects strikes me as the biggest oversight.

The +20 Will save it has isn't terrible. But you can get a DC of, what, 32 on Dominate Monster? That's a solid 60% chance of getting yourself a pet tarrasque.

I was thinking of giving it all 4 Protection from effects, which would pretty well cover it from most mental things, but ya, that is a hole it has.

Option 1: have you considered making it an elder evil? The signs are good world enders?

That is an option, but I always viewed the Tarrasque as basically Godzilla. It's from the Material Plane and he exists to restore the world to "balance". Typically by wrecking the face of the great civilizations of the time.

So its an option, but it isn't my first choice.

My biggest suggestion would be giving the Tarrasque some aura that makes it outright immune to anything originating from more than say 30-50 feet away from it. If you try to fly outside its reach pinging it, you're not impacting it at all. If you can hurt it, it can hurt you back.

Honestly its numbers are scary enough where they are for the majority of characters, so from there other changes I would make include:
-Shore up weakness to Ability Drain and status effects. If you send in an Allip, it does nothing.

-Give it some ability to ignore high level defenses. Probably mindsight or true seeing to straight up ignore things like greater invis and mirror image. Give it the ability to roll multiple times against regular miss chance, taking the best result. Ideally find some way to deal with Immediate Action "take a bonus turn" effects that render its attacks useless.

-Make it more of a threat to surrounding areas. Its attacks deal multiplied damage against buildings. It can stomp/smash people, when attacking it hits a small aoe so it can crush armies quickly and efficiently, nullifying minionmancy effectiveness and also punish players for grouping up too closely.

-I don't actually like giving the Tarrasque maneuvers/stances, just for flavor reasons, but giving it some feats to take advantage of its combat reflexes would not go amiss. Hold the Line+Knockback to screw with chargers, Mage Slayer/Pierce Magical Concealment/Pierce Magical Protection is a good set of options as well (and better than what I suggested earlier with rolling twice on miss chance).

That Aura idea is really good actually. It's mere presence warps space forcing you to fight in closer where the warping isn't as big of a deal. Even if the range is 100 feet, so long as his base speed is upped he can always reach you during his turn.

Telepathy and Mindsight would be great on him and let him pretty much beat everything.

#1: Give Tarrasque Abomination-traits. Essentially it is one already so it should have them. This also gives it Divine Rank 0 by D&D, which gives it a neat array of extra stuff.

#2: Yeah, pick useful feats. Lethal charges, some ranged attacks (PF style Spine attack for instance or Destruction Rains from the Heavens á la Lavos from CT).

Going gown Abomination, the Tarrasque is like 80% of one already, and it would make it immune to Drain, which is good.

* Remove all toughness feats, give it one improved toughness feat.
It gains HP and has several open feats for customization this way.

* Remove awesome blow.
It sucks.

* Go ahead and remove cleave, great cleave, improved bullrush.
These feats are to make the Terrasqua terrifying to commoners. Each commoner killed gives it extra movement and an extra attack allowing it to rapidly kill low-hp opponents each round, destroying entire towns in mere seconds. But players are uninterested in this trait, it's useless against them, and as the DM you control pacing & placing anyway.

Agreed. 1 Feat for 48 HP is probably still worth it, but all the other crap isn't helpful.

* Trade one of those feat slows for brutal throw.
It's attack bonus it also high enough to make anything into an improvised weapon.

* Trade four of those feat slots for an epic destiny.
Demigod gives it a divine rank value, greater restoration, and miracle covering it's weaknesses. Eternal Hero gives a Final Fantasy X Sin vibe as well as an extremely versatile 1/day ability. If nothing else body outside body creates 8 additional pseudo-terrasquas and is an excellent theatrical opening.

* Use 3~4 feat slots on martial study & martial stance.
Devoted spirit plays into the more divine/primordial nature, thicket of blades takes advantage of it's reach & combat reflexes and it can be combined with Robilar's gambit given it's considerable bite attack. Strike of righteous vitality allowing it to heal ability drain once per encounter as well. This also cycles back to the duplicates from eternal hero since they can use strikes to heal the original and increases the number of AoOs a creature will get hit by each round.

Let it chuck buildings. Check.

Demigod makes the tarrasque hilariously durable, by giving him an HP reset button. That is great. Aaaand Eternal Hero is that +1 and the Tarrasque just refuses to stop. I kinda love it.

And I like that list of Maneuvers. They aren't flashy and seem mundane enough for the Tarrasque to do them.

I think we're making a truly terrifying beast here.

[Biffoniacus_Furiou]

Make it Divine Rank 0, which automatically changes its land speed to 140 ft. and gives it immunity to energy drain, ability drain, and ability damage, among other things.

Add the Half-Fiend template, which gives it a fly speed and makes its natural weapons count as magical so it can hit incorporeal opponents. That also gives it eight base skill points per HD, and may add more class skills depending on its fiendish half (or just add Hide and Move Silently to its class skills). Give it 51 ranks in Listen, Spot, Search, Survival, Hide, and Move Silently, and with its ability to fly into the clouds or use Darkness as a spell-like ability, it should be able to reliably sneak up on potential prey.

Change its feats to include Quicken Spell-Like Ability a few times, maybe Empower Spell-Like Ability: Horrid Wilting, and Magic in the Blood so all those spell-like abilities are usable 3/day. Also give it Improved Spell Resistance (epic) at least three times, which ups its SR to 41+ so the Wish that's intended to end it may just bounce off. Also give it Diehard, assuming that allows it to continue acting as though it's disabled instead of falling unconscious. It doesn't specifically call out working with nonlethal damage, which the Tarrasque takes due to regeneration, but the Frenzied Berserker class sets a strong precedent (otherwise Deathless Frenzy wouldn't even work as frenzy inflicts nonlethal damage every round and he'd fall unconscious from that). Also consider including (Improved) Rapidstrike for its claws and horns, and Improved Flight for better maneuverability.

Keep in mind that this monster has a caster level 48 Blasphemy, which automatically kills nonevil creatures with 38 or fewer HD. If the party is expecting to fight it and the PCs do some research ahead of time, they should know to use Greater Spell Immunity ahead of time to avoid being killed outright.

[Malphegor]

Would giving it defenses against mind magics help? I’m thinking 5 ft thick lead plate armor to prevent spells penetrating?

[Elves]

Don't do things that compromise its identity. Tome of Battle stuff is too fancy for it, as are most SLAs. Don't make it fancy, fiendish, draconic or outsidery. It's a big primordial brute.

Just give it a bunch of immunities, mind blank, freedom of movement, etc. Pretty simple.

Upgrade its carapace to have a permanent spell turning/epic spell reflection effect.

4e gave it a 1000ft no fly aura. If the improved carapace isn't enough you could extend that to a 1000ft antimagic field.

Higher speed yes, but teleporting or flight are against its fantasy. It says no to other people, rather than keeping up with them, and just keeps ravaging. If you don't use the no fly aura, definitely give it an enhanced Earthbind ability.

Permanent Foresight could be good. No Disjunction, that makes it too magical by virtue of being counter-magical. It just doesn't care.

Abomination doesn't fit since that gives it a bunch of languages and telepathy. Divine Rank 0 is a good suggestion.

[Eldariel]

Honestly, the big thing it needs though is interaction with magic. On high levels, being immune to damage is pretty easy through at least 3 different avenues. As you said, it also makes sense as a "cleanse the world"-kinda monster. Thus some kind of "disjoins an effect per round (at random?)"-effect with some kind of manual supercharge á la "disable all magic within 1000 miles for 5 rouns" as a per hour sort of deal could make sense. This would at least make sort of sense and make it a bit less predictable and more frightening without fundamentally altering its nature. Oh and for pete's sake, make its guts Dead Magic and its Improved Grab ignore FoM.

[MaxiDuRaritry]

Remember, ToB maneuvers don't have to be martial arts. It's not like, say, a pistol shrimp using its claws to create a cavitation bubble hotter than the sun to deal fire damage is a martial art. It's just a useful effect that is inherent to the pistol shrimp's physical and instinctual nature. The same could be said for any maneuver you give to Tarry the Tarrasque. Iron heart surge? Its physical and mental toughness allows it to throw off any status effect it's dealt. It heals itself when it strikes another creature due to siphoning off its foes' health with vampirically-charged claws and bite. It can full attack after a charge because it's a literal combat monster.

I don't see why these things have to be martial arts.

[Elves]

Then I would just give it the abilities you want, rather than using TOB maneuvers. Updating underpowered NPCs with splat material is fun but the Tarrasque should be dead simple, plain and implacable.

[Sutr]

Horrible idea but one I once thought about big t could be slow due to its stomach being a sphere of annihilation...

[MaxiDuRaritry]

Then I would just give it the abilities you want, rather than using TOB maneuvers. Updating underpowered NPCs with splat material is fun but the Tarrasque should be dead simple, plain and implacable.

ToB gives ways to improve the tarrasque that are already extant, and swapping feats is easy.

[Endarire]

Our level 21 group didn't fight the Tarrasque the normal way: It was used as the hull of the mothership for an alien invasion. Of course, guns and other things were added.

[Sereg]

I agree that the flavour and themes should be kept. Ground bound and no fly zones seem too supernatural for this purpose to me. Spike throwing and a roar that acts as a sonic breath weapon with windstorm and knockback effects that can be switched between bursts, cones and lines at will seems fitting to me. Along with insane jump bonuses.

Treat it as mindless when advantageous. Then immunity to ability drain/damage etc.

It needs a way to affect the ethereal. Treat it as ghost touch? Adamantine also fits.

Maybe teeth and claws that grant auto-sunder attempts and disjoining saliva and stomach acid. I like its stomach being a dead magic zone.

True seeing fits.

The simpler manuevers work. As does brutal throw. Maybe treat it as having dungeon crasher? Not that walls are really relevant to it.

[Mato]

Remember, ToB maneuvers don't have to be martial arts. It's not like, say, a pistol shrimp using its claws to create a cavitation bubble hotter than the sun to deal fire damage is a martial art.

Flavor can be whatever the player imagines.

Like an eternal hero tarrasque doesn't "cast body outside body", it's chopped off remains accidentally regenerate a new beast. It's chomp doesn't "cast heal", rather with a surge of it's stubborn survivability it heals something everyone in this thread says it should have been immune to. In fact, sell the entire thing as the tarrasque is so old the primordial gods experimented on it with the idea of rejuvenation leading to the creation of the foul beast's irksome healing. The spells vigor, regenerate, and even heal came centuries later and are actually refined adaptations that came about from studying the monster's innovative abilities.

[Anthrowhale]

I liked several of the suggestions around feats so I made a statblock with improved feats / skills.

Spoiler: Tarrasque redone

Show

Size/Type: Colossal Magical Beast
Hit Dice: 48d10+624 (1107 hp) //maximum hit die for divine rank 0
Initiative: +7
Speed: 180 ft. (36 squares) //quadruped colossal divine rank 0
Armor Class: 37 (-8 size, +3 Dex, +30 natural, +2 deflection), touch 7, flat-footed 34
Base Attack/Grapple: +48/+82
Attack: Bite +58 melee (4d8+18/18-20/×3)
Full Attack: Bite +58 melee (4d8+18/18-20/×3) and 2 horns +53 melee (1d10+9) and 2 claws +53 melee (1d12+9) and tail slap +53 melee (3d8+9)
Space/Reach: 30 ft./20 ft.
Special Attacks: Augmented critical, frightful presence, improved grab, rush, swallow whole, large and in charge, mage slayer, pierce magical concealment, pierce magical protection.
Special Qualities: Carapace, damage reduction 15/epic, immunity to form altering attacks (polymorph, petrification, etc...), immunity to mind-affecting effects, fire, poison, disease, energy drain, ability drain, and ability damage, regeneration 40, scent, spell resistance 32, death denied, regenerative touch at will, divine surge 1/day, miracle 1/day, divine immortality
Saves: Fort +39, Refl +29, Will +30
Abilities: Str 46=45+1(inherent), Dex 16, Con 36=35+1(inherent), Int 3, Wis 14, Cha 14
Skills: Listen+10, Search-4, Spellcraft-2, Spot+57, Survival+2
Feats:
1. Combat Reflexes (+3 AOOs/round)
3. Power Attack (Up to +48 to damage for attacks)
6. Improved Initiative (Init+4)
9. Endurance
12. Steadfast Determination (PHB II, Con to Will saves, Fort not autofail on 1)
15. Large and in Charge (Draconomicon, Control AOO movement)
21, 24, 27, 30. Epic Destiny: Demigod
33. Blindfight (roll twice to penetrate concealment)
36. Mage Slayer (Will +1, threatened cannot cast defensively)
39. Pierce Magical Concealment (spells don't cause miss chance)
42. Pierce Magical Protection (spells don't improve AC, dispel such on hit)
45. Toughness
48. Pain Mastery (Str+2 / 50 points of damage)
Environment: Any
Organization: Solitary
Challenge Rating: 20
Treasure: None
Alignment: Always neutral
Advancement: 49+ HD (Colossal)
Level Adjustment: —

W.r.t. Blackhawk48's OP complaints:

1. Now immune to ability drain via demigod.
2. Move 180' as a quadruped colossal demigod, but still ground bound.
3. Much better feats adding Epic Destiny:demigod, Large and in Charge, Pain Mastery, Mage Slayer, Pierce Magical Concealment, Pierce Magical Protection, and Steadfast Determination.
4. Pierce Magical Protection allows more attack bonus to be dumped into power attack. Pain Mastery adds to strength for every 50 points incurred during an encounter. Apparently this strength is only lost at the end of the encounter so the Tarrasque could easily end up with a Strength bonus of +300. Also, I believe that DR/Epic counts as 'magical' w.r.t. attacks, so incorporeal creatures are not immune.
5. Demigod shores up defenses with mind-affecting, form-altering attacks and ability drain immunity. Steadfast determination shores up the 'weak' save. Divine Surge provides complete hitpoint recover 1/day. Death Denied increases saves vs. necromantic effects by 5, provides mettle vs. necromantic effects, and rerolls 1s vs necromantic effects.
6. Still no ranged attack. The best option I can find is the Savage Species version of Fling Enemy. However, this is technically overridden by the much more meh Races of Stone version. The 1/day Miracle does potentially provide an option.

In addition, I shifted almost all the skill points into Spot. With a +57 modifier, the Tarrasque can see through invisibility easily and has an excellent chance of observing enemies at substantial distances.

[MaxiDuRaritry]

Pierce Magical Protection allows more attack bonus to be dumped into power attack. Pain Mastery adds to strength for every 50 points incurred during an encounter. Apparently this strength is only lost at the end of the encounter so the Tarrasque could easily end up with a Strength bonus of +300. Also, I believe that DR/Epic counts as 'magical' w.r.t. attacks, so incorporeal creatures are not immune.

Is there any way to base your hp on your Strength score? Because gaining more HP due to taking damage would be h4x.*

Also, no, overcoming DR does not allow you to hit incorporeal creatures. Your attacks must either be +1 or better, or they have to specify that they can hit incorporeals. What if you give him some enhancing item that makes its claw attacks count as ghost touch? Either a +1 ghost touch necklace of natural weapons (with a few extras) or some other way to make its attacks actually magical and actually ghost touch. Make him incorporeal somehow and give him Ghostly Grasp?



*Take 50 hp of damage, gain +48. Combined with regeneration would make him extremely difficult to take down via hp damage without one-shotting him.

[flappeercraft]

To be entirely honest, to avoid the Tarrasque being underwhelming I just use this thing instead

[Anthrowhale]

Is there any way to base your hp on your Strength score? Because gaining more HP due to taking damage would be h4x.*

X to Y suggests no, unfortunately.

Also, no, overcoming DR does not allow you to hit incorporeal creatures.

For the incorporeal subtype, we have:

An incorporeal creature ... can be harmed only by ... creatures that strike as magic weapons...

I'm not sure what this can mean other than DR/magic or DR/epic creatures which strike as magic weapons for the purpose of overcoming DR/magic. Is there a different interpretation?

[Sereg]

Oh yes. Let it shatter force effects and give it infinite deflection

[Mr Adventurer]

Is there a general rule about DR overcoming DR? Because I see a lot of later creatures with Magic Strike as a SA, or the ability to overcome a certain DR with their natural weapons called out in their block.

You should be aware that Pierce Magical Protection requires its own standard action attack.