fantastipotamus Share definition Flag an animal suggested by a daughter of Ron Howard in an episode of The Simpsons. it only sings three times a day. "Hurry daddy or we'll miss the fantastipotamus! She only sings three times a day!" fantastipotamus by ColdFusion July 12, 2003 0 0 Get merch Get the fantastipotamus mug. Buy Now — $32.95 See more merch