Acro Bot is a robotic orca created by the Haltmann Works Company. It is based on the design of Acro, an orca native to Planet Popstar and Aqua Star. The robot has blue eyes, a gray dorsal side, and a white underbelly. It has a blue dorsal fin, pectoral fins (which are positioned at the middle of its body), and a propeller in the place of a tail. Acro Bot has a row of small, sharp teeth in its mouth and seven small holes on its face.
Steam Hammer appears exclusively in Stages 5 and 7 of Overload Ocean and Stage 7 of Access Ark. It swims around the ocean depths in circles endlessly, passing between planes as it does so. If Kirby is struck by the enemy, he is either launched directly into the screen or into the distance, depending on where he was hit in the robot's arc. Both cause Kirby to drop his Copy Ability. Acro Bot is immune to all attacks and is best avoided.
The seven holes on Acro Bot's face appear to be a speaker, though the enemy does not produce any internal noises.
When Acro Bot launches Kirby into the screen, a cloud of bubbles is released on impact.