Goku's Ascension - S1.E35

After Baby flees from defeat by the claws of the ape, Goku finally transforms into a Super Saiyan 4! With his power increased to its maximum, Goku sets out to find where Baby is hiding and finish him off for good. But with Bulma's help, Baby might just be able to find the strength inside his Saiyan host to bring himself up to, and even, Goku's power level!