The Wheel of Slime was a wheel that gave you from 100 NP up to 2,000. It was free to play and couldn't hurt your pet, take away money, or take away an item, making it one of the best wheels. There were 3 different versions of it (each showing a different set of characters) but you couldn't spin extra times by switching to a different version. You could only spin one of these wheels every 8 hours.
It was sponsored by Nickelodeon, the previous owner of Neopets, so it was decorated with Nick characters.
Now that Neopets is run by Jumpstart, this game and any other Nick sponsor games have been removed. Sponsor games do not end up in the Game Graveyard when taken down.