The Ground Shaker (地面揺らし Jimenyurashi?), also known as the Hammer Punch, is an attack used by Knuckles the Echidna in Sonic the Hedgehog (2006). When using this move, Knuckles dives into the ground and creates a shockwave to attack foes.
When performing the Ground Shaker, Knuckles jumps into the air, then dives straight downward with fists first and spins his entire body around rapidly while giving off a flaming red aura. Knuckles then impacts the ground with his fists with such force that he creates a disruptive shockwave along the surface to damage the surroundings before jumping back on his feet.
When used in gameplay, the Ground Shaker can not only damage enemies but also paralyze them, leaving them immobile. To perform the Ground Shaker in gameplay, the player must press / during a jump. Once the attack begins, however, it cannot be interrupted before Knuckles hits a surface.
- The Ground Shaker resembles the Drill Claw used by Knuckles in Sonic Adventure 2 and its remake, Sonic Adventure 2: Battle. The main differences being that the Ground Shaker damages and paralyzes enemies, cannot penetrate the ground, and cannot be interrupted.