Needle Storm is a move that Sheik can perform in Super Smash Bros. Melee and Super Smash Bros. Brawl for the GameCube and Wii, respectively. The move is executed by pressing the special move button (usually the B button), and is an attack that can be charged by keeping the button held. Once ready, Sheik will then toss the needles that she's held towards an opponent.
It's suggested that the move be used far away rather than close up, as it does have lag time to pull the needles out, thus giving your opponent the upper hand.