Bernie Bridges --- the smartest schemer on the Rotten School campus with a million tricks up his sleeve. It was Bernie who got the cafeteria lady to call Milky Way bars a vegetable. It was Bernie who convinced the Headmaster to enroll a dog in school. Who organized the Blueberry Barf-off and the Super Slimy Slug Race? Bernie, of course. What would Rotten School do without him?

Belzer --- Bernie's best friend and most loyal slave who does all the boring, daily chores, which frees Bernie up for the more important tasks of planning and scheming. Belzer needs to work on his self-esteem and his favorite extracurricular activity is peeling the scabs off his knees and eating them. But when Bernie needs someone in his corner, Belzer is always there.

Crench and Feenman --- Bernie's henchmen. Crammed into a room across the hall with Belzer, they're often the first to know about Bernie's latest, greatest ideas. They're also always willing to pitch in and help out --- whether it's coming up with a Three Stooges Act for the talent show or breaking the football team's 1,500-game losing streak.

April-May June --- the hottest, coolest girl at Rotten School. She's Bernie's girlfriend, though she doesn't know it yet. With a flick of her blond ponytail, she turns down all of Bernie's invitations. But Bernie is not giving up. He knows there's a scheme that will open April-May's eyes; he just has to keep scheming until he finds it.

Sherman Oaks --- Bernie's arch enemy. His parents buy him every imaginable gadget, from a watch with 42 functions (including a fire extinguisher!) to a digital drum machine. Rich, snooty and so far from cool that he lives in Nyce House, Sherman nonetheless has the attention of the impressionable April-May. No matter.  Bernie always manages to turn the tables on Sherman --- and if they occasionally pull a stunt together, they have their reasons.

Mrs. Heinie --- dorm mother and fourth grade core teacher. She's a favorite of Bernie and the gang, mostly because she's not that hard to confuse. But despite this, the guys can count on Mrs. Heinie to save them from their worst mistakes.

Headmaster Upchuck --- the short, squat and bald headmaster who waddles like a duck. He manages to stay out of Bernie's way most of the time --- which is a good thing for Bernie, since he's not as easy to confuse as Mrs. Heinie. Headmaster Upchuck is responsible for reading the morning announcements each day, including information about student activities like the Maggots' Club and the Long Distance Sneezing Contest.

Jennifer Ecch --- Also known as Nightmare Girl, Jennifer is so big and strong she can carry Bernie around in one hand. And because she's in love with him, she frequently does.

Gassy --- Bernie's dog (the name says it all). Just make sure, if Bernie picks YOU to walk her tonight, you walk in front of her and not behind her!

Chipmunk --- the shiest kid in Rotten School. He's so shy he never looks up and plays his guitar in the closet. But if anyone can pry him out of his shell, it would be Bernie!

Beast --- eats anything and everything, including whole pizzas (plus boxes) and dead slugs he finds on the bottom of his shoe. Of course, a human garbage can does come in handy sometimes!

Billy the Brain --- the smartest boy at Rotten School. He studies for half an hour every night and maintains a C- average. When Bernie needs to pick someone's brain, he knows exactly who to pick.

Mr. Skruloose --- a new teacher who expects Bernie and his friends to do pushups, laps and even homework. He runs his class like an army, and is tough enough and mean enough to break a ruler with his bare hands. It's a good thing that Bernie can charm even the most hardened of teachers --- or Rotten School might be in for some changes.

Mrs. Twinkler --- As drama coach at Rotten School, you'd think she'd have her hands full selling tickets, designing sets and ordering costumes. But Mrs. Twinkler really has only one job: choosing the most responsible, hardest working student to be director of the play. (You can see where this is going, right?) Famous for her "twinkle and shine" slogan (or is it "tinkle and shine"?), she manages to get a surprising amount of work --- and money --- out of her drama students.

B.A. Gool --- one of Rotten School's most prestigious alumni. During his school days, he was famous for picking bugs out of his hair and late night meetings with sea creatures in Pooper's Pond. Now, the whole world knows him for his enormously popular horror movies, including the EEK films (EEK III: The Warts Are ALIVE and EEK IV: Revenge of the Warts) and the Bugs on My Face trilogy.