Itchy

From Muppet Wiki

Itchy is Grundgetta's pet Rottendoodle -- a grouchy dog breed. Grundgetta shows off her dog to Oscar in episode 4127 and encourages him to adopt his own Rottendoodle.

Unlike Oscar's dog, Cranky, Itchy is a properly grouchy pet. He's dirty, and he doesn't do anything that Grundgetta tells him to do.