Seeing as I've already done alot, I guess you expect high hopes from me!

PORRIDGO:
The Porridgo was one of the latest creatures (2017 BC (Before Chex) :P ) to evolve into a non-human food form (Flemoid). They are made of a delicious porridge. Due to their high body sugar, it was inevitable that the Shreddans (See below) would hunt them to near-extinction and make Porridge out of Porridgo young. To counteract this, a Porridgo evolved into a Flemoid. Natural selection ruled the other Porridgos out, and to this day Flemoids still exist.
SHREDDAN:
Arguably one of the most sucsessful prehoristic creatures. Made of Shreddies (English Chex) you could say "Everything English turned out best!" But that's besides the point. Inventing a prehistoric 'Zorcher' (Transalates to Rock Flinger in modern English Latin) they hunted Porridgos until the tides turned and they had to go into hiding. Evolving, they became Chexonians, became smart and migrated to Ralston.
CHEESI:
Made of blue cheese. I don't know why, I don't know when. I think they evolved because they couldn't stand the smell. As Chexonians only recently found out about Kadil, not much is known about them.
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Hope you like! :)