From Muppet Wiki

A Disagreeable Sandwich appeared on the "Cliff's Nightmare" episode of The Cosby Show. A sausage and peppers submarine sandwich with a layer of Swiss covering his mouth, the sandwich spoke with a vaguely Teutonic accent and repeatedly argued with Cliff Huxtable (played by Bill Cosby).

The sandwich was only one of several Muppet food characters to appear in the episode. The closing gag revealed a refrigerator containing a talking tomato, scallions, cabbage, carrots (all recycled from The Muppet Show), a pineapple (seen on Sesame Street), cake, and cheese wedge.

In The Secrets of the Muppets, Jim Henson briefly put the sandwich puppet on his hand and performed him as a demonstration.