The Grim Adventures of Invader Zim is an American animated science fiction-supernatural-comedy television film serving as a crossover between Invader Zim and The Grim Adventures of Billy and Mandy, being co-directed by Jhonen Vasquez and Maxwell Atoms. It is produced by Cartoon Network Studios, Warner Bros. Animation and Nickelodeon Animation Studios and it will premiere on CBS All Access on March-August TBDth, 2021.
As another tentative to take over the Earth, Zim discovers a portal that allows him to find another dimension where an entity known for working for two young children is tired of its life and has TBD.
- Richard Steven Horvitz as:
- Zim, a megalomaniacal and arrogant Irken invader who has found TBD.
- Billy, TBD
- Harold, TBD
- Rosearik Rikki Simons as GIR, TBD
- Grey Griffin as Mandy, TBD
- Greg Eagles as the Grim Reaper, TBD
- Andy Berman as Dib Membrane, TBD
- Melissa Fahn as Gaz Membrane, TBD
- Vanessa Marshall as Irwin, TBD
- Rodger Bumpass as Prof. Membrane, TBD
- Kevin McDonald and Wally Wingert and Almighty Tallest Purple and Red, TBD
- Jennifer Hale as Gladys, TBD
- Diedrich Bader as Hoss Delgado, TBD
- Candi Milo as Ms. Bitters, TBD
- Olivia d'Abo as Tak, TBD
- Phil LaMarr as Count Dracula, TBD
- C.H. Greenblatt as Fred Fredburger, TBD
- This is the third crossover between a Warner Bros. and a Nickelodeon property, with the first and second being Velocity and Samurai Jack: Demon's Edge and Batman vs. Teenage Mutant Ninja Turtles.