PAC-MAN originally appeared in his classic 8-bit form from the arcade games that gave him popularity. He could be considered the only "playable" Assist Trophy character, as he could be controlled with the player's movement keys, and was the only Assist Trophy character to do so. PAC-MAN followed a straight path whenever a key was pressed. Characters did continue moving though, so they had be careful while using PAC-MAN.
PAC-MAN chomped the opponents he came into contact as if they were the ghosts from PAC-MAN (this after the sound effect that is heard when he chomped someone), dealing 16% of damage with greater knockback.