Chompy is the pet Chain Chomp of Iggy.
In part 3, Chompy attacked Bowser Jr. (dressed up as Mario), being the last enemy to start attacking him.
When the Mario Fan Club was attacking the airship, Iggy used Chompy to eat a Mario Fan Club member.
In Part 2, he was sleeping. When Bowser Jr., Lemmy, and Iggy begin their adventure, they ride with Chompy out of the airship to Castle Koopa. In Part 3, Ludwig was chained to him.
- He is the same Chain Chomp that appeared in New Super Mario Bros. Wii.
- He is able to fall from high places (such as the airship) without getting hurt.