1) Something uglier than the grundle or the taint, or both combined
2) Someone is a bitch
3) Cute name for a pet fish
4) A long lost Pokemon
"Hey man, check out that chick, she's a real grundle-taint."
"Vern, you're such a grundle-taint."
"Can you feed Grundle-Taint while I'm on vacation?"
"Sweet man, I caught me a grundle-taint."