The Rapid Crab (ラピッドクラブ) is an enemy robot that appears in Sonic Rush Adventure.
Rapid Crabs are crab-like robots much like other crab-related Badniks in the series such as Crabmeat and Gamigami. Found in Coral Cave and related Hidden Islands, they will scuttle back and forth in their designated areas. Unlike most other crab robots, Rapid Crabs will stop and attack by repeatedly thrusting their claws in the air above them for a few seconds once approached by the player, then will carry on scuttling. It is a bad idea to jump on a Rapid Crab when it is attacking, but Boosting or Spin/Burst Dashing into it will still take it out easily.