Ucantia Defeatus[1], which is a pseudo-scientific name corruption of the phrase "You can't defeat us", is an enemy class in Super Mario World 2: Yoshi's Island and Yoshi's Island: Super Mario Advance 3. Enemies in the class Ucantia Defeatus can be defeated only a certain way. Enemies in this class include Piranha Plants, Tap-Taps, Boos, Zeus Guys, Bandits, and the game's bosses.