Headclicker
Headclicker or Head Clicker is used to describe someone who is very good at landing headshots in shooter-type video games. Someone who clicks heads, and lands headshots.
Jerry: Jesus Christ, that guy can't stop landing headshots!
Mikey: He's nuts man, that guy is a professional Headclicker.
Mikey: He's nuts man, that guy is a professional Headclicker.