Avenger Penguins The story revolves around three bike-riding Penguins that inhabit Big City, uniting to protect it and its citizens from the evil Caractacus P. Doom, an insane and reclusive criminal scientist. The Penguins attempt to prevent Doom's schemes but find themselves often hampered by their own miscommunicating and occasional scraps with other biker gangs infesting Big City, such as The Stink Brothers, a canine squad of Hell's Angels.