Extended Grapple
Samus's Extended Grapple is a technique in Super Smash Bros. Melee. It allows Samus to extend her grab attack, among other features, including homing onto enemies.
Application
The way to extend Samus's grappling beam is press Z, then up, down, and up on the control pad, then Z again. This combo must be inputted between frames 8-39 of the grab (the part of the grab before the grapple becomes visible). Samus's grapple will extend to approximately 3 times its normal length. One can also home onto opponents by pressing L when you pull it out. However, opposed to the normal grappling beam, one needs to press A or Z when the tip of the beam is over the enemy in order to grab your opponent.
Samus is not able to perform this technique in the PAL version of SSBM.