Elvis the Mouse

Alright listen up, genius. The joke here is that the person's pet mouse was named "Elvis," like Elvis Presley, the famous singer. The mouse died because it was caught in a trap. Get it? "Caught in a trap" is also the name of an Elvis song. So the joke is that the mouse literally got caught in a trap and it's a play on words because of the song. But hey, I wouldn't expect you to get it if you didn't know Elvis was the King of Rock and Roll. You probably think music started with that mumble rap you listen to.