Rock'n (ロックン in Japan) is a badnik found exclusively in Sandopolis Zone.
Due to its resemblance to the sand-blocks found in the Zone, many players jump on Rock'n in an attempt to break it. However, when approached Rock'n springs up and begins pacing towards the player's character. Unlike traditional badniks, Rock'n cannot be smashed by simply jumping on top of it due to the solidity of its outer shell. The player must use the Spin Dash on Rock'n's lower half in order to defeat the badnik and free the creature inside. Rock'n does not have any damaging attacks as such and cannot cause direct harm to the player, though he can push the player into harm's way such as crushing platforms, which unsurprisingly is where they are often found.