Assist Trophy

An Assist Trophy is an item that, when grabbed, summons a random non-playable character to aid the player who summoned him. Assist Trophies work nearly identical to Poké Balls. However, no Pokémon come out of them, and once an Assist Trophy is grabbed, it is automatically activated, assuming the holder is standing on the ground, and not in a jump, attack, or hitstun. Basically they are "guest" characters separate from the playable roster.

Only one Assist Trophy (and the character it releases) can be in a match at once. The next Assist Trophy will not appear until the data for the character it will release is fully loaded.

List of Assists Trophies

 * Bandana Dee: Charges at opponents, very weak and can be beaten.
 * Light Yagami: Uses the "Death Note" notebook to summon a Shinigami that drags a single opponent off-screen.
 * Rock Lee: Effect unknown.

External link

 * What are Assist Trophies?