Dragon Ball Z

Synopsis

After absorbing Vegito, Buu notices that he has not taken on any of his characteristics. He guesses this is because he hasn't digested Vegito yet. Inside Buu, Vegito still exists intact, and separate from Buu. It turns out that Vegito had planned this, putting up a barrier during the absorption, and letting himself be shrunk by Buu's magic absorption process, but not incorporated into his being. Once he dispels the barrier, Vegito unexpectedly splits back into Goku and Vegeta. Taking advantage of this unexpected event, Vegeta crushes his fusion earring, not wanting to give up his independence from Goku by permanently fusing with him. He cites that once they free their absorbed friends, Buu will lose most of his power and they won't need to be fused to defeat him. As they journey through his innards, they encounter tiny green pieces of slime The slime starts to attack, and it completely covers Goku, electrocuting and paralyzing him. Suddenly, a giant worm appears, ready to eat Goku.

(Source: Wikipedia)