Doctor: Well, it looks like your gluteus maximus has made a full recovery.
SpongeBob: My what has a what now?
Doctor: You're butt's all better. It's really quite amazing. It took twenty hours to putt it all back together. We actually ran out of staples and had to use glue stick. Yep, you're a lucky, lucky, lucky, lucky, lucky luck-boy. But from now on, I'd like you to be more careful. One more injury like that and you could wind up like that poor creature there with the iron butt.
Fish with iron butt: Oh man, it itches!