Irwin, Hoss Delgado, Jeff the Spider, Fred Fredburger, and General Skarr from the "Grim Adventures of Billy and Mandy" team up to fight an evil candy army from the Underworld on Halloween. Grey DeLisle, Greg Eagles, Richard Steven Horvitz, Vanessa Marshall, Diedrich Bader, Armin Shimerman, C.H. Greenblatt Added on HBO 2023-05-17.