ass-weevil

A derrogatory term used to refer to one who is like an anal itch that you can't quite get rid of. More directly, it compares an extremely annoying person (usually a pestering co-worker) to a small burrowing insect that has made its home up your ass.

The term itself was most famously coined in a fit of rage by one Mat Noguchi, the notoriously hostile tools developer for Bungie Studios (creators of the Halo video game franchise).