|First appearance||Super Mario 3D World (2013)|
|Latest appearance||Super Mario 3D World + Bowser's Fury (2021)|
King Ka-thunk (known as King Kathunk in the British English version of the original game) is a boss that appears in Super Mario 3D World and its Nintendo Switch port Super Mario 3D World + Bowser's Fury as the boss of World 5-Castle: King Ka-thunk's Castle. He is a small, blue metal square with red shoes and detached red hands. He also has five spikes on the front (one of which is positioned like a beak right below his eyes) and his back is pink and fleshy with an X-shaped bandage over it. King Ka-thunk floats in the middle of another, larger Ka-thunk frame that his hands hold on to.
He serves as the boss of World 5. His main attack is moving around the Ka-thunk frame before finally stopping in one of the corners. After this, the ground that King Ka-thunk will fall on glows red before he crashes into the ground, damaging any players caught under him or his frame. To damage King Ka-thunk, the player has to jump on his backside while he is facing down. Oddly enough, he is not damaged if a player is thrown onto his weak spot by another player. After each hit, two of the arena's corners will fall off, and King Ka-thunk will become faster and more erratic. Once three hits are landed, King Ka-thunk is defeated, several circles of Coins appear, and the Warp Box to the Goal Pole is revealed.
King Ka-thunk later reappears as one of the bosses in World Flower-12: Boss Blitz with the exact same strategy from his first battle in World 5.
|Super Mario 3D World||content/ObjectData/BossWackun.szs||BossWackun||Boss Ka-thunk|
Names in other languages
Kuāng Dāng Wáng
|Pun on「框」(kuāng, frame) and「哐当」(kuāngdāng, the sound of crushing objects) +「王」(wáng, king)|
|French||Roi Klonk||King Ka-thunk|
|German||König Klonk||King Ka-thunk|
|Italian||Re Clompo||King Ka-thunk|
|Portuguese||Rei Quadrapumba||"Rei" (king) + portmanteau of "quadrado" (square) and "pumba" (onomatopoeia for thumping)|
|Pun on "каркас" (karkas, frame) and possibly "кар" (kar, the sound of a crow)|
|Spanish||Rey Marcoplás||King Ka-thunk|
- Level name: King Ka-thunk's Castle