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.
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.
- While the name "Rock'n" comes from Japanese material such as Japanese Sonic Jam Official Guide book, game design documents of Sonic the Hedgehog (Didj) confusily lists the Badnik as "Corkey" alongside its Japanese name. Another Badnik with name Corkey already exists at Launch Base Zone.
- Sonic the Hedgehog (Didj) game design document, pg. 7.
- Japanese titled enemies of Sonic & Knuckles listed on the GHZ.
- (in Japanese) ソニックジャム オフィシャルガイド. SoftBank. 2 October 1997. p. 83. ISBN 978-4797303377.