Piccolo uses the Special Beam Cannon technique in an effort to destroy his arch-enemy, Goku. He does this using a technique called the Special Beam Cannon. This technique allows him to fire a powerful laser beam from his fingertips.
Piccolo performs the technique by touching his fingers together and then charges up enough ki to perform the technique. As soon as he has enough charge, he extends his fingers outward and releases two thin streams of energy from the tips of his fingertips. The result is a strong beam which can pierce most targets in a straight line.
While the move can be used without any charge, its true strength is unleashed if Piccolo has enough time to fully-charge it. During this process, Piccolo is left vulnerable.