Harpies's Clique: Monster-Human Alliance
The members are constantly plastering the cafeteria with flyers, passing out pins, and all that jazz. They print "Make Love Not War" on their promotional materials, but sometimes they don't really practice what they preach. The Harpies definitely don't help the group's reputation very much because they have a tendency to steal everybody's food in the cafeteria and then poop on the crumbs.
These one-eyed giants are known for their bad tempers and dim wits. They also have a nasty habit of eating whomever they come across. The most famous member of the tribe is Polyphemus who was blinded by Odysseus, but there are many more of 'em: Brontes, Steropes, and Arges are the sons of Uranus and Gaia, who got locked up by both Uranus and Kronos for the crime of being big and scary.
This angry dude is half-man, half-bull, and spent most of his life locked up in the mysterious Labyrinth on the island of Crete. Like the Cyclopes, the Minotaur was known for munching on a person or two every once in a while. His people-munching ways didn't last long, though, because the Athenian hero, Theseus, came and stuck him with a sword.
This might be the only club where Medusa could possibly be considered "the pretty girl." Medusa is a Gorgon, a snake-haired creature so ugly that she turns people to stone whenever they look at her. (Yeah, that's about as ugly as it gets.) Medusa was killed by the hero, Perseus, who chopped off her head.
In the epic Anglo-Saxon poem Beowulf, Grendel is a man-eating demon that lives in the land of the Spear-Danes and attacks King Hrothgar's mead-hall, Heorot, every evening. The narrator of Beowulf claims that Grendel's motivation is hearing Hrothgar's bard sing songs about God's creation of the world, which rubs his demonic nature the wrong way. Whatever the reason, every night, Grendel slaughters more Danes and feeds on their corpses after tearing them limb from limb. Although he can't be harmed by the blade of any edged weapon, Grendel finally meets his match when the Geatish warrior Beowulf takes him on in a wrestling match.
In the Odyssey, Homer tells us that Circe is a beautiful sorceress with a tendency to turn men into animals when they venture onto her island. She's an immortal woman with magical powers, who (after turning his men into pigs) convinces Odysseus to stay with her on her island for one year. She lives on this island attended by ladies-in-waiting and surrounded by animals who were once men. Sounds like a sweet life, no? Eh, maybe not. She's pretty lonely.