Chopped liver
Chopped liver only appears in the episode Growth Spout. In that episode, the chopped liver can talk, as can the biscuit lying beside him in Mr. Krabs' cupboard. Both have apparently gone unnoticed by Mr. Krabs for sometime. The chopped liver is mostly used just as a gag, for when the biscuit says "What am I, chopped liver?" The chopped liver says, "No, that's what I am."