One of the potions, used by Professor MacKrill.
MacKrill's Potions are the marine liquid vials of Professor MacKrill, able to turn a human into a marine creature or vice versa. Originally featured in the animated movie, Help! I'm a Fish, the Potions of MacKrill are featured in the villains tournaments, either by the evil mastermind, Joe, to achieve his goal of world domination, or either, when Fly, Chuck, and Stella are turned into marine creatures, in Heroes vs. Villains War, though this time they are used by Yzma, or either by Professor MacKrill, himself, when he uses the potions to revert the newly transformed Ariel, Tiana, and Naveen, into their former state, although only Ariel succeeds in being restored.