Groundchuck and Dirtbag are a mutant bull and mole from the 1987 Teenage Mutant Ninja Turtles episode, Planet of the Turtleoids.
They were both once animals at the City Wild Animal Park where Shredder was about to test mutagen on a lion and a gorilla to use them to steal a ruby at a museum. However, a turtleoids named Kerma entered the zoo and freed the lion and the gorilla. Just then, a bull and a mole came in, freed by Bebop and Rocksteady, and the bull hit the mutagen dispenser with his head, which spilled mutagen on the two animals, causing them to transform into Groundchuck and Dirtbag. Shredder and Kraang came in and were shocked to see them mutated, instead of the lion and the gorilla. Nonetheless, Shredder gave them clothing and told them to go to the museum to steal the ruby. Groundchuck asked him why they should do that. Shredder replied by ordering them to. The two mutants, however, disobeyed Shredder and escaped. They later ran into the ninja turtles and broke into combat with them. Just then, Kerma captured them and dragged them into a building, which turns out to be his spaceship.