Through a mix-up in paperwork, twelve-year-old Adam Lyon is accidentally transferred to Charles Darwin Middle School, where all of the students and faculty are animals. As the only human student, Adam soon finds that life at his new school really is the survival of the fittest.
Adam is a 12-year old human who was transferred to a school for local zoo animals because of an accidental misspelling of his last name from "Lyon" to "Lion". Adam was paired up with troublemaker Jake Spidermonkey in gym class, and now they're best friends.
Jake Spidermonkey is Adam's best friend. He hates not having Adam around regularly, and although he can be lazy and selfish, Jake's also a very good friend. He has also a slight obsession with his backside.
Ingrid Giraffe is easily the tallest student in Charles Darwin Middle School. Her height makes her feel insecure, so she tries - unsuccessfully - to blend into the background and not get attention. Ingrid has a crush on Adam Lyon, but she tries to keep this a secret.