The American animated television series The Grim Adventures of Billy & Mandy features a cast of fictional characters created by Maxwell Atoms. The series, which originally aired on Cartoon Network from June 13, 2003 to October 12, 2008, follows two children, a dimwitted, yet well-meaning boy named Billy (voiced by Richard Steven Horvitz) and a brilliant, yet sinister girl named Mandy (voiced by Grey DeLisle). After winning a limbo game to save Billy's pet hamster, the two gain the Grim Reaper (voiced by Greg Eagles) as their best friend for eternity, and come across a variety of supernatural or otherworldly characters and locations throughout the series. Billy, Mandy, and Grim are the main protagonists of the series. Irwin is a secondary character or also a main character in the show. Othe