Shellcracker, called Punch Crab (カニパンチ) in the Japanese manual, is a badnik from the 16-bit version of Sonic the Hedgehog 2 found in Metropolis Zone. It is a crab with a giant claw. When the player approaches one from the side it will suddenly extend its claw and try to attack. They can often be found in corridors with low ceilings, making it difficult to pass their backside. In order to defeat one, the player must hit the vulnerable side that lacks the giant claw.
Shellcracker's name is misspelt "Shellcraker" in one of Sonic Jam's Sonic World galleries.
The enemy reappeared in Sonic Pocket Adventure's Gigantic Angel Zone.
Shellcracker, as seen in Sonic the Hedgehog 4
The enemy is also in Sonic 4's Mad Gear Zone. Concept artwork for a Shellcracker badnik was released to fans as part of a Project Needlemouse promotion on SEGA America Blogs on January 15, 2010. Shellcracker also made an appearance on Sonic's 19th Anniversary Contest website.