A mondegreen is the mishearing (usually unintentional) of a phrase as a homophone or near-homophone in such a way that it acquires a new meaning. Like this: There's a bathroom on the right (the line at the end of each verse of "Bad Moon Rising" by Creedence Clearwater Revival—"There's a bad moon on the rise") 'Scuse me while I kiss this guy (from a lyric in the song "Purple Haze", by Jimi Hendrix—"'Scuse me while I kiss the sky"). "Olive, the other reindeer ...", from the song "Rudolph the Red-Nosed Reindeer" misinterprets the line "All of the other reindeer . Have at it!
"I was born on a pile of shit", heard when someone is holding one's own tongue and saying "I was born on a pirate ship"