The Drill Claw is a move performed by Knuckles the Echidna. It first appeared in Sonic Adventure 2 and Sonic Adventure 2: Battle, where Tikal the Echidna also could perform this move. It is a offensive spinning drop that the user attack his opponents with. It is the equivalent to Rouge the Bat's Drill Drive.
To use the Drill Claw, the user must be placed in midair, be it from a jump or from gliding in air. When performing the Drill Claw, the user will then dive directly down through the air while spinning, with his/her fists pointing downward and will damage any enemy the user comes in contact with below him/her. This is similar to the Spiral Upper. If the user (In Knuckles' case he must possess the Shovel Claws) makes contact with digable ground while performing the Drill Claw, the user will automatically perform Dig. The performance of the Drill Claw can also be stopped before reaching the ground, allowing the user to either fall normally or resume the Glide, making the Drill Claw a good way for the user to quickly descend while gliding. In Sonic Adventure 2 and its remake, Knuckles' Drill Claw can be enhanced with the Hammer Gloves, which allows him to break iron craters.
In Sonic Adventure 2 while performing the Drill Claw, Knuckles will dive down so fast that he leaves afterimages.