Billy Thunderman

William "Billy" Thunderman is a main character on The Thundermans. He is the middle child and the youngest son of the Barb and Hank Thunderman.

BackStory
Billy was born mid-air on the way to Metroburg Hospital as revealed in the episode, A Hero Is Born. This could explain why he is not as smart as the rest of the family. He moved to Hiddenville with the rest of the Thundermans and enrolled in Hiddenville Elementary School with his sister Nora.

Billy is not the smartest kid but Nora helps him figure things out, both in school and at home.