Puppet Pals Mitch and Clem (voiced by: Rob Paulsen and Tom Kenny) are puppets seen in a TV show during the episode Mommy Fearest. Their appearances parody of 2 Muppets, Bert and Ernie, from Sesame Street and they also perform behind a Sesame Street-like wall. Their main sketch is Mitch bonking Clem on the head, which is most likely a reference to classic puppets Punch and Judy.
Puppet Pal Mitch (voiced by Rob Paulsen) is always on the right of the screen during the Puppet Pals Show. He styles a purple colored "bonker," which he uses to hit Clem in almost every skit. He wears a white shirt with a red bow tie similar to Pee-wee Herman's. He sports a somewhat puberty-like voice.
Puppet Pal Clem (voiced by Tom Kenny) is the lesser known of the duo. He is shorter than Mitch, and wears a hat with a flower on it, along with a striped shirt. He receives a bonk on the head by Mitch in every episode, and has a voice like that of Barney, one of Homer's buddies at the bar, from the hit TV series "The Simpsons" (the mentioned character is voiced by Dan Castellaneta in the mentioned series).