Son Goku uses the Janken for the first time to defeat a confused Bear Hybrid.
The Janken is an attack Son Goku used during the earlier chapters of Dragon Ball, one he learned from Son Gohan Sr. The attack is essentially a mind-game, using the Rock, Paper, Scissors collocation to confuse the enemy and striking with something they don't expect.
A variation of the technique exists in Dragon Ball Online and is learn-able at Level 1 by Martial Artists.
Rock Paper Scissors