Kerotaur, what an orc is to a man, this is to a centaur (PEACH)

[inuyasha]

Kerotaur
Size/Type:Large Monstrous Humanoid
Hit Dice:9d8+45 (85 hp)
Initiative:4
Speed:30 ft (6 squares)
Armor Class:16 (-1 size,+0 dex, +7 natural), touch 9, flat-footed 16
Base Attack/Grapple:+9/+21
Attack:Longspear +16 melee (1d10+12)
Full Attack:Longspear +16 melee (1d10+12)
Space/Reach:10ft/5ft
Special Attacks:Powerful Charger
Special Qualities:Darkvision 60ft.
Saves:Fort +8, Ref +6, Will +4
Abilities: Str 26, Dex 10, Con 21, Int 8, Wis 7, Cha 8
Skills:Listen +6, Spot +6
Feats:Alertness, Endurance, Improved initiative, Weapon focus (longspear)
Environment:Temperate Hills
Organization:Solitary, Mating pair, Tribe (3-20), Killing stampede (20+ with orcish riders and ogre support units)
Challenge Rating:7
Treasure:Standard
Alignment:Usually CE
Advancement:10-14 HD large, 15-18 HD huge
Level Adjustment:-

Before you is a strange, feral beast with the lower body of a shaggy rhino, and an upper body that is malformed and resembles an orc
These creatures are exactly like what a centaur is, though with an orc and a rhino. There is one thing very different however, though they have the mind of orcs, they are much more feral, and as such never gain class levels, instead growing bigger and bigger.

Combat

Powerful Charge (Ex)
Keeping true to their rhinoceros origins the Kerotaur can set any piercing weapon (as well as some slashing ones with a pointed straight edge like a longsword) to do double damage, those which can already do this do triple damage instead.

[Debihuman]

With BAB +9, full attack should show 2nd iterative attack with manufactured weapon. Full Attack: Longspear +17/+12 melee (1d10+12). I like it's a reach weapon. BAB + Size modifier + Str modifier + weapon focus should be +9, -1, +8, +1 = 17 not 16.

I could see these in conflict with a pride of wemics. BTW a group of rhinos is a crash (or stubbornness).

Is there a reason these don't wear armor?

Debby

[inuyasha]

With BAB +9, full attack should show 2nd iterative attack with manufactured weapon. Full Attack: Longspear +17/+12 melee (1d10+12). I like it's a reach weapon. BAB + Size modifier + Str modifier + weapon focus should be +9, -1, +8, +1 = 17 not 16.

I could see these in conflict with a pride of wemics. BTW a group of rhinos is a crash (or stubbornness).

Is there a reason these don't wear armor?

Debby

Well the centaur doesn't, and with how purposefully feral these things are I don't think they would like barding very much, they've got a hefty magical armor. It could be ok on specific individuals, but I think in general they wouldn't.