The Scamander, a petpet, produces slime that is great for helping cricky necks. (This information was the answer to the Daily Puzzle on the 24th day of the month of Collecting.) It can be Blue, Pink, White, Plushie, Custard, Dung, Clay and Faerie.
They have also been known to be donated to the Money Tree by a fake user called "scamander_in_chief" who seems to be a Neopets Staff. If you want to get one from the money tree, be fast, because they crawl out of hands.