Headbutt, sometimes formatted as Head Butt, is the side-special move used by Donkey Kong in the Super Smash Bros. series, starting with Super Smash Bros. Melee. It is performed by pressing the special move button (usually B) while tilting the Control Stick or Circle Pad to the side.
When the player performs the move, Donkey Kong rears his head slowly in the direction he is facing and then quick slams it down. If any opponent is hit by Donkey Kong, they are momentarily buried into the ground. If Donkey Kong performs Headbutt while the opponent is airborne, it is meteor smas]ed to the ground. Headbutt can break shields, most noticeably in Super Smash Bros. for Nintendo 3DS/Wii U, where the Headbutt can shrink even a full shield to its smallest size.
Donkey Kong can perform Headbutt in midair, and stops the move as slams his head down (regardless whether he has hit an opponent). Unlike his other moves, Giant Punch and Spinning Kong, Donkey Kong does not become "helpless" in midair by performing Headbutt.
In Super Smash Bros. for Nintendo 3DS/Wii U, there are two unique variants of Headbutt that can be used as custom moves:
Jumping Headbutt adds a jump before the Headbutt, which executes faster than normal. However, the move's bury effect is shorter, and Donkey Kong risks self-destructing himself if he uses this move off-stage.
Stubborn Headbutt executes slower than the default Headbutt, but during the execution period, Donkey Kong is given super armor, and the attack is more powerful when it connects with any opponents.