Ka-thunk

Ka-Thunks are invincible enemies that only appears in the courses King Ka-Thunk's Castle and Bowser's Lava Lake Keep from Super Mario 3D World. Ka-Thunks look like spiky blue squares which hurt the player upon contact. They usually spawn in small crevices and move along a set path until they fall into an abyss. The boss of World 5, King Ka-Thunk, is their leader.

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