Pikachu (SSB)/Neutral attack
Pikachu headbutts forward, doing 2% damage for each hit and Pikachu can headbutt rapidly as much as it likes when the player presses the A button rapidly. When it uses the move rapidly, it is easy to chain with the other headbutts. And with its good shield stun, it can break a opponent's shield on a wall and can be used to perform a jab grab, where Pikachu stuns an opponent with this move and follows with a grab. It does have high ending lag once Pikachu is done using this move however.
The move also has slightly higher base knockback in the Japanese version making it slightly more effective at lower percents but slightly less effective at higher percents.