One of the manifestation of Steve's conscience, he appears in Comic 7 and Comic 66, advising him to stomp on a bug and push a button, respectively. While seemingly harmless acts on their own, these actions invariably lead to near-fatal disaster for Steve both times.
In addition to being a manifestation of Steve's conscience, the Shrimp has also appeared as a sort of announcer. First, he announces the cliff-hanger-esque ending in Comic 7. Later on, he appears at the end of Comic 38 to announce the moral of the story.