The Return of Senior Senior and Junior

"The Return of Senior Senior and Junior" is the fourth episode of Kim Possible comics. It is notable for being the introduction of the characters Senior Senior and Junior. Despite the name of the episode referring to a "return" of these characters, this is their first introduction in the comics. This is because at this point in time the comics were still seen as a spin-off of the Kim Possible TV show, in which both of these characters are enemies of Kim Possible.