A person that has had sex with a dead body. It is the most severe insult that could ever be placed upon a person. Mother Fucker is nothing compared to it, as a mother could be any woman, but a corpse is a dead body no matter what.
alternate fan-based name to the song titled "Prince Caspian" by Phish. This secondary moniker came about as an expression of displeasure upon hearing the song, which is arguably one of the weaker songs played in a typical Phish set (also known as a bathroom-break song). Origin is unclear, though came into popularity in fall/winter of 1997. Tapes and setlists circulated among the fans commonly have this song listed as Fuckerpants instead of Prince Caspian.
Useage of this moniker seems to be more prevalent per-capita among Phish tapers than the overall scene.
1. "Dude, set two was raging until they killed it with Fuckerpants."