Dragon Ball Z Episode 31
Saiyan Sized Secret
Vegeta and Goku continue their one-on-one battle of strength, will, and determination. Blow by blow, the two warriors seem evenly matched, until Vegeta reveals the secret power of the Saiyans?the ability to transform into a giant ape, whose rage is capable of destroying entire civilizations and planets! Can Goku find a way to stop this monstrous assault?