|First appearance||Super Mario 3D World (2013)|
|Latest appearance||Super Mario 3D World + Bowser's Fury (2021)|
Ka-thunks are obstacles that appear only in the courses King Ka-thunk's Castle and Bowser's Lava Lake Keep in Super Mario 3D World and its Nintendo Switch port, Super Mario 3D World + Bowser's Fury. Ka-thunks resemble metal blue square frames covered in spikes that hurt the player upon contact. They either spawn in small crevices and move along a set path until they fall into an abyss, or appear moving in a looping path. Some simply flip from side to side. They function similarly to Tox Boxes, as they move along paths, and the player must avoid them by using the hollow space in the middle. They cannot be destroyed by any means, including invincibility, excluding a pair of Ka-thunks in Bowser's Lava Lake Keep that disappear upon defeating a pair of Hammer Bros.
King Ka-thunk holds on to a larger Ka-thunk during his battle.
|Super Mario 3D World||content/ObjectData/Wackun6x6M.szs||Wackun6x6M||Wackun, a romanization of「ワックン」(Wakkun); play on「枠」(waku, frame) and possibly a reference to「ドッスン」(Dossun, Thwomp)|
Names in other languages
|Pun on「ガチン」(gachin, onomatopoeia for slamming noise) and possibly a reference to「ドッスン」(Dossun, Thwomp)|
|French||Klonk||From English onomatopoeia "clonk"|
|German||Klonk||Same as French name|
|Italian||Clompo||Masculine form of "clomp" (the sound of a crushing object)|
|Portuguese||Quadrapumba||From "quadrado" (square) and "pumba" (onomatopoeia for slamming noise)|
|Spanish||Marcoplás||Portmanteau of "marco" (frame) and "plás" (sound of a crushing object)|
- Musa, Alexander, and Geson Hatchett. Super Mario 3D World PRIMA Official Game Guide. Page 27.
- Shogakukan. 2015. Super Mario Bros. Hyakka: Nintendo Kōshiki Guidebook, Super Mario 3D World section, page 225.