Ham Sandwich
A person of which that would be eaten, like a ham sandwich, by higher class people in case of an end-of-the-Earth situation. In other words: a low class loser.
Student #1: Geez! That kid over there still has not done his end-of-the-year presentation and it was due 3 days ago.

Student #2: He's the ham sandwich of the class. Don't worry about him.