More flumphs than you can shake a flindbar at: Let's Read the Tome of Horrors!

[Rappy]

Gryph
A four (or sometimes six)-legged ibis that implants its eggs in living organisms. ...Just...I don't know what to say about it...Dungeons and Dragons! *Throws up hands in defeat*



Guardian Daemon
While not quite a true daemon (indeed, they are listed as being True Neutral with "evil tendencies", and they are creations of the daemons for summoning purposes), this CR 7 Outsider certainly isn't to be underestimated. The guardians resemble a mixture of animal (usually an ape, bear, or big cat) and horned daemon and watch over rooms or treasure stores...you know, the typical D&D monster job. A guardian daemon attacks with both its arsenal of claws and teeth, but can also expel a 30-foot gout of fire to snipe targets at a range; this is rather useful, considering that the guardian daemon must stay in a designated 100+ (10 extra per caster level of the summoner) square foot region. While not especially inspired, the guardian daemons are a good gateway drug for later adventures with true daemons.



Hangman Tree
Most likely formed after a few too many ghost stories, the CR 7 hangman tree is a hellish oak with noose-like tentacles for grappling opponents and hallucinogenic spores that can make an opponent believe it is either a treant or a mere oak in the woods. It's also weak against electricity and cold, for whatever reason, and is slowed by darkness spells (again, for whatever reason). The more interesting thing than the monster itself, though, is the fact that this idea was apparently good enough that Necromancer Games decided to do it twice. In the Tome of Horrors II, there is a similar creature known as the gallows tree. The two major differences are Challenge Rating (7 vs. 13) and the fact that the gallows tree took a page from the yellow musk creeper's book and creates plant zombies.



Haunt
The haunt, a CR 4 incorporeal Undead, is essentially a ghost-lite; it can transform into a will-o'-wispy light ball, deal Dexterity damage, and possess a living being, but not much else. It also suffers from some somewhat contradictory flavor text. The haunt is obsessed with achieving rest at last, since the cause of its death has trapped it within a 60-foot boundary zone around the place where its body fell. How does it do that? Why, by mercilessly assaulting with its Dexterity drain and then hijacking the paralyzed body for its own purposes, of course! Just in case you forgot that undead are under contract to be malevolent.



Hellmoth
A giant CR 6 Aberration of a moth. Envelops foes and sets them on fire. Not as interesting as such a premise would indicate.



Hippocampus
A classical Greek legendary "merhorse" with human-level intelligence. Good for sea-going characters and NPCs, particularly aquatic elves and the like, bad for Let's Read purposes. I don't really have that much to say about them, really.