It is a small Krabby Patty with a face that has small pickles for eyes, ketchup for pupils and a smile, and little antennas on it to make it look like a cute bug. It comes in the Krusty Kids Meal and includes a bib and high chair.
The Pipsqueak Patty costs more even though it's smaller than a regular Krabby Patty.
It is served to Barnacle Boy by Squidward as if he were a little child. Everyone in the restaurant surrounds him and starts to laugh and make fun of him. Barnacle Boy refuses to eat it because he thinks he is too old to be eating "immature" food that is really meant for children. This is also one of the reasons why Barnacle Boy becomes "evil" in the episode.