Grimer is a Poison-type Pokemon which is a giant blob of, well, grime. And extremely toxic poisons. And some other things that shall not be named. It apparently evolves into the curious Muk at some level (I dunno, look it up on Serebii!)
Ash Ketchem and his terrorist squadron first encountered Grimer messing around in Farts Fly for Magnemite! where Ash's evil Pikachu started acting all weird (which they find out later was because of a Magnemite that was in love with Pikachu for some reason). The Grimer stick their sludgy butts into a power plant, which causes the power to go out, so Ash decides to investigate. He meets the Grimer and their Muk leader and pretends to compliment their smell, but Misty (being the idiot she always is) says it smells like crap. Then they run for their lives. (Un)fortunately enough, Pikachu's lover arrives with his own terrorist squadron and zaps the Grimer to their death. Ash then stupidly stuffs the Muk leader into a Pokeball, which makes him smell for weeks afterward.
- Professor Oak (widely known as Professor Tree Name) uses Grimer as fertilizer.
- Grimer is Remirg spelled backwards, which translates into literal Igbo as "child abuse".
- Koffing is Grimer's long lost brother's plumber's dog's previous owner's sister's mother-in-law.
See also: Muk