How about this for a Halo 2 creature you've never heard of before: a Drinol Beast, a sort of hairless, gray monster with one eye - although there are other drawings of it with two eyes so you can't take for granted that it's going to make the final game.
Sharquoi, previously known as Drinol, are a Covenant species that was cut from Halo 2. They are huge beasts that are kept contained and segregated from the other forces, similar to the way Hunters are deployed in the other Halo games. They possessing phenomenal strength and are often used to smash.
- Conversations from the Universe (Mentioned only)