The term mondegreen - meaning misheard lyric - comes from from Sylvia Wright's mishearing of the "Oh, they have slain the Earl of Moray and laid him on the green" as "Oh, they have slain the Earl of Moray and Lady Mondegreen". Here are a few examples:

'Scuse me while I kiss this guy
Beelzebub has a devil for a sideboard
Killed in a bar when he was only three
Olive the other reindeer used to laugh and call him names
The ants are my friends, they're blowing in the wind
The girl with colitis goes by
There's a bathroom on the right