From the Super Mario Wiki
Smoke Ball is an item in Super Smash Bros. Brawl. However, it doesn't do much damage. Once thrown, it will emit colorful smoke into the air, which can be very distracting to the players. It is also hard to see what moves are being used, and it is difficult to see what's going on. Players can pick up the item, and take it, or throw it somewhere else. It can also be thrown onto players, in a similar fashion to a Gooey Bomb.
Trophy Information from Super Smash Bros. Brawl