Fireball is Mario's Neutral Special move in SSBTUF. Mario shoots a fireball from his hand, and the fireball travels forward bouncing. It is much faster than in previous Smash games and Mario can now shoot two fireballs quickly in a row.
Mario first threw fireballs in Super Mario Bros.. The power was obtained by getting a Fire Flower. The Fire Flower is a recurring power-up in the Mario series and has appeared in every Mario platformer to date. In some sports games, Mario is shown to be able to manipulate fire withouth a Fire Flower.