Rock'n (ロックン Rokkun?)[1] is an enemy that appears in Sonic & Knuckles and its locked-on expansion Sonic the Hedgehog 3 & Knuckles. It is a mass-produced Badnik model created by Dr. Robotnik.
Appearance
Rock'ns are disguised as breakable sand blocks found in the Sandopolis Zone. When they rise up, they display a pair of black eyes and a grey lower body with blue legs.
Overview
In Sandopolis Zone, Rock'ns are not easily discovered due to their resemblance to the local sand blocks. When the player approach them, the Rock'ns will rise up and begin pacing towards the playable character.
Rock'ns do not have any offensive attacks to use against the player. However, they can push the playable characters into harm's way, such as crushing pillars which (unsurprisingly) are placed close to them. Rock'ns cannot be smashed by Spin Jumping on top of them due to their outer shell. Instead, the player must use the Spin Dash on the Rock'ns lower half to defeat them.
References
Template:Sonic 3 & Knuckles info