The series revolves around four children: Billy O' Toole, Marcus and Ruby Snarkis, and Lydia Lopez. The series' main antagonists are Earl P. Sidebottom, AKA The Phantom and his rat sidekick Ratticus. Earl is a boy genius who some time before the series' beginning got a "D" grade in shop class and retreated to the school's sub-basement boiler room in shame. In there, he built a supercomputer capable of altering reality, which he uses to cause chaos in the school as revenge, leaving the protagonists to stop him.
Characters
Ashley Brown as Billy O'Toole – One of the main protagonists. He wears a red baseball cap with a B logo on it because he plays baseball. He dislikes taking baths because he thinks they are boring without his imagination.
Tracey Moore as Marcus Snarkis – An African-Canadian boy who is Billy's best friend and classmate. Marcus has a great knowledge of computers and carries around a mini-computer called a Megamind, which helps him solve problems. He is Ruby's younger brother.
Tracy Ryan as Ruby Snarkis – Marcus's older sister. She is sometimes hot-headed, but still cares for her friends and Marcus. Her goal in life is to become an actress.
Terri Hawkes as Lydia Lopez – A girl of Hispanic descent who is one of Billy's classmates. She is often shown wearing a green dress and her hair is tied into pigtails. She is considered the smartest girl in her grade level, even going by Earl's standards. Lydia is one of the brains of the protagonists as her knowledge helps them get out of traps.
Richard Binsley as The Phantom/Earl P. Sidebottom – Earl is the antagonist of the show. He is the boy genius who, in his past, got a bad grade in shop class and went to the boiler-room in shame. His personality is that of an evil genius; however, the downside is that he is also very childish. He builds a giant super-computer which alters reality and depending on the theme of each episode, the computer can alter the appearance of the school. However, most of Earl's schemes usually backfire mainly thanks to the kids, and mostly ends with the destruction of the computer. He prefers being called "the Phantom," but he doesn't mind having the protagonists call him by his real name.
Ron Rubin as Raticus – The Phantom's bumbling pet rat who carries out his schemes. Raticus is not very bright as he is often insulted and treated badly by Earl due to his lack of intelligence.
Eddie Glen as Fred Spurtz – The school pig. He likes eating bugs and fish. He usually hangs out with the other protagonists.
Lindsay Leese as Mrs. Snodgrass – The children's class teacher. She is very caring about the students in her class and always makes sure they follow her rules. She often uses The Phantom's school transforming schemes to help teach the class.
Len Carlson as Principal Buzz Mulligan – The principal of Flying Rhino Junior High, in which he is in fact an anthropomorphic rhinoceros. He is usually oblivious to anything odd going on in the school; however, he is portrayed as a caring, respectable administrator. He also appears to be a retired ace pilot. Hence, the school's name.
Paul Haddad as Buford – The janitor of Flying Rhino Junior High. He is an anthropomorphic pig, similar to how Principal Mulligan is an anthropomorphic rhino. He sees himself as a secret agent and sometimes helps the protagonists through situations, whether or not they're made by Earl.
Eddie Glen as Johnny Descunk – A troubled classmate of the protagonists who sometimes gets sent to detention, and hangs out with the other kids.
Ron Rubin as Rod – Rod is Johnny's best friend. He happens to have the same intelligence level as Raticus.
