Dragon Ball Z Episode 18

Gohan continues his martial arts training under the watchful eye of Piccolo, but a strange transformation takes him over. A full moon causes the young Saiyan to rampage out of control! Meanwhile Goku finally makes it to the end of Snake Way and mistakes a friendly ape named Bubbles for the mythical King Kai. With two of our heroes going bananas it looks like the two sinister Saiyans will have an easy time invading Earth!