"Ambush!" (罠 Wana, lit. "A Trap") is the three hundred fifth chapter of Dragon Ball Z and the four hundred ninety-ninth overall chapter of the Dragon Ball manga.
Buu lands and smirks, as Gohan thinks nothing seems to have changed. Trunks thinks Buu will just run away again. Boo looks over and yells that he wants to fight the youngsters again. Gohan refuses, saying he is Buu's opponent, but Buu insists that he wants to settle the score with them before fighting Gohan. Gohan wonders why, but Buu ignores him and accuses the boys of being too scared. Trunks and Goten each say that they're not, and Piccolo thinks something weird is going on. Trunks tells Piccolo that Buu is too stupid to have any sort of plan. The two then quickly perform Fusion. Gotenks starts off in his Super Saiyan 3 form, calling himself Super Gotenks, the death god of justice. Buu thinks to himself, "With the youngster's power… and that Piccolo guy's brains…" Gotenks flies over next to Gohan, and to let him fight. Buu oozes a little bit of his back off into two blobs, and the blobs slide across the ground unnoticed.
As Gotenks prepares to fight, one blob envelops him, while the other blob takes Piccolo. With a flick of his finger, Buu brings the two blobs back to him. As he absorbs them into his body, he begins to transform. Goku wants Gohan to hurry and kill him now, but Buu's transformation is over before Gohan can react. Buu lets out a sigh and looks down at Gohan with a devilish grin. His forelock is now elongated, extending down to his knees, similar to that of a Super Saiyan 3's hair, and he is wearing Gotenks' vest. Boo thinks aloud that this is truly the birth of the strongest majin. Gohan can't believe this, but Buu says it's all Gohan's fault for getting stronger. He felt Gohan's existence from far away, and thought that he might be stronger, so he started planning. His suspicions were confirmed when they fought, which was when he realized he'd be the strongest if he absorbed Super Gotenks. But, since his power had a time limit, Buu decided to wait until the next chance. Gohan says Buu's stupidity still hasn’t changed, as it would’ve been smarter to just absorb him. Buu realizes Gohan doesn't get it and tells him there's no point of being the strongest if there's no one to fight and killing him is his greatest motivation. Gohan smiles, saying he gets it now.