The main character is Eric Wimp. He is a schoolboy who lives in Nuttytown. When he eats a banana, Eric transforms into the adult superhero Bananaman, who has the basic Superman powers. However, Bananaman is accident prone and moronic often defeating the villains by mistake. He can eat bananas for extra powers (although how this works varies from story to story). He has a weakness for moldy bananas. He has a Fortress of Solitude-like headquarters in the North Pole and a sidekick Crow (a talking version of his namesake).
Bananaman was a parody of Superman, Captain Marvel and various Silver Age superheroes. The comic was characterized by eccentric British humour and slapstick. The main character was given two origin stories:
- Eric was an alien from the moon that was sent to Earth. The explanation for his powers is that because bananas look like crescent moons.
- As a baby, he accidentally ate a banana that had "saturnium" hidden in it by Doctor Gloom.