All the monsters

Alistair
Basilisk
Blindheim
Blood hog
Blue leopard
Blue gorilla
Blue scorpion
Carrion crawler
Caryatid column
Cobra
Crawling claw
Crow-skull children
Crystal lizard
Death's head moth
Deodand
Dividing demon
Evil cat
Firewurme
Fractal frog
Fractal ooze
Frog abomination
Gelatinous dodecahedron
Giant house centipede
Golem, birdcage
Golem, glass
Green knight
Gurgler
Hagfish
Harpy
Imp
Komodo dragon
Lion
Little hairy men
Lizardman
Mechanical cricket swarm
Mermalant
Moon beast
Moss hog
Ogre
Purple octopus
Red slime
Salamander
Skeleton archer
Skeleton, bonebride
Skeleton, knight
Skeleton, gigantic
Skeleton, mancatcher
Skeleton, piper
Skeleton, regenerating
Slaad
Sphinx
Spinosaur
Vampire
Vampire monkey
White elf
Witch
Wolf
Wolf-head men
Zombie
Zombie ooze

That's it so far.  I make up my own stats for all these monsters, because I run a 3.5-light game and all the 3.5 edition monsters have health and armor-class that's way too high, and all their powers are copy-pastes of the most boring spells.  

Basilisks don't have six legs.  Salamanders are small and extremely magical and live in fires.  Blindheims are the only correct blindheim, which is to say that they are a toad so ugly that to gaze upon it is to go blind, and they are native to Abazidun the Black Jungle, and must drink the milk of a drunken goat and eat the larvae of the veridian bot-fly in order to maintain their power.  I've mentioned that Thomson's bard has a blindheim in a hooded lantern - he is always on the look-out for goats, since his goats keep getting lost or killed by vampires.  The firewurme is not a dragon or dragon variant . . . but I won't say more to risk spoiling it.

Witches are necessarily Frazetta witches.

I can't account for the plethora of blue monsters and environments - aside from the ones listed, they've also fought a blue priestess of the Angel of Colors who stole Dirtface's color; groped through a thick blue smoke that the wizard Palethorp summoned to defend his tower; and found an underground blue jungle grown by the light of an orb held aloft by a statue of Zuggtmoy, Queen of Putrescence.  Blue gorillas have four arms and speak the language of dreams (several of my players are currently dream-infected with a blue gorilla they slew, and which threatens to burst from their psyches every time they dream).  As in Vornheim, to dream of a blue leopard means to meet one the next day.  Blue scorpions have an electric sting, I think, I lost that paper.  Ostrid the Blue had blue scorpion earrings and she threw them to the ground like firecrackers, and they appeared in a cloud of blue smoke.

Slaad are of the old, patient and extremely bored toad-man variety, and cast weird spells like ennui, duo-dimension, vomit slime, tar body, and stone-like-water.  Skeletons move the way they do in "Jason and the Argonauts," my players understood but I pulled up the video anyway.  Frog abominations are the monsters from Hellboy.  Deodands are grey-skinned naked tall guys who can swallow people whole, and live in the wastelands west of Belmric.  Sphinxes think very highly of themselves, and are revered as gods by the pygmies of Ovgalad.

Mermalants are dogs with beautiful long white hair and the hands of men.  They speak human language, sleep in offal, can exhale a cloud of biting flies, and were inspired by Kate Bush's hit single "The Hounds of Love."  (To my players: this doesn't necessarily mean you'll meet more if you follow the map to the Tower of Love)  The only one they ever met was named Tiny Bell, and he was a guard in a sanitarium in Olomoc, City of Plazas.  He pretended to be their friend after they killed his companions, a mathematician and a psychoanalyst, and then at his first chance fled outside into the snow.  Tiny Bell is probably still on his way home.