look up any word, like cunt:
 
1.
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."

2. David Bowie > Possum > fuckerpants, Frankenstein, Harry Hood
by GrampsMI March 22, 2009
 
2.
Some one that comes to randomly mess with people when they are busy with a task. Guerilla warefare, as they usually attack and run off.
"I was under the car on a creeper and that fuckerpants Tim kicked me in the balls and took off before I could roll out and kick his ass."
by Timmy 2 tone September 17, 2006