Vegito(Dragon Ball Z Profile)

This is Vegito, an insanely powerful being that was formed when Goku and Vegeta merged together by using the Potara Earrings, a set of earrings that was given to Goku by the Elder Kai. The fusion was necessary and the only way to stop the almighty Super Buu, who was granted unequal power when he absorbed Gotenks, Piccolo, and Gohan.

Vegito mostly resembles Goku in stature, while his facial features are mostly from Vegeta's. Also, in this form, he seems to be twice as cocky as Goku already is, and as arrogant as Vegeta. Vegito's personality is the very opposite of Gogeta's. Gogeta is calm and serious, while Vegito is talkative and a joker - he loves annoying his opponent. Nevertheless, he has the power to easily overcome even the mightiest of the foes. It was never confirmed which of the two fused Saiyans controls Vegito, since he displays all the characteristics and behaviors of the two.

Unlike Gogeta, Vegito only appeared once in the series. He would've appeared again when Kid Buu was about do destroy the planet, but Kibito Kai did not make it in time to give the earrings to Goku and Vegeta, and the energy ball already touched the ground before the two could even put the earrings on.

In Dragon Ball GT, Vegito could've made an appearance as a Super Saiyan 4 if the Potara Earrings still existed.

The Elder Kai stated that a fusion via the Potara Earrings is more efficient than the one made by the Fusion Dance, but he never stated the resulting warrior to be much stronger than the one made by the Fusion Dance method. However, the Potara Earrings still provide a little boost in power, which is why Vegito is a bit stronger than his fusion counterpart, Gogeta, but the difference between their powers is almost non-existant. Fans tend to speculate that Vegito is much stronger than Gogeta, but it's not true. Even at his base form, Vegito's power and speed were already a lot greater than a Super Saiyan 3's(at least during the battle with Super Buu since Full Power Super Saiyan 3, which was supposedly attained by Goku after the Kid Buu Saga would've actually been stronger than Vegito), and he was more than a match for the horrifying Super Buu, who had recently reached an unprecendented power level by absorbing Gohan whose powers equaled SSJ3 Goku's. He could withstand devastating energy blasts from Buu that would most likely annihilate Goku and Vegeta if they were fighting separately, and he was able to catch Buu's giant energy ball that could split the planet in two and kick it back up to Buu's direction just before it exploded.

Since the Potara Earrings provide extra boosts in strength, in Vegito's base form, his level of power is about equal to Super Buu's. He only seemed to have the upper-hand against Buu because he possessed the superior fighting prowess of the two Saiyans. When Vegito transformed into a Super Saiyan, his already impressive power was multiplied by several times(possibly by fifty times, as is the case with any Super Saiyan) that he could've destroyed Super Buu if he wasn't planning on being absorbed in order rescue the Z-Fighters that Buu absorbed. Even when Buu turned him into a coffee-flavored candy, he was still able to land bone-shatterring poundings on Buu. Just before Kid Buu destroyed the Earth, the Elder Kai mentioned that if Vegito were to fight Kid Buu, Vegito would make short work of the weaker version of Buu.

In Dragon Ball GT, SSJ4 Gogeta could've annihilated Omega Shenron if he was aware of the time limit of the fusion. It is theorized by fans that if there was still a set of Potara Earrings, then a new being even more powerful than Gogeta would be born and rub out the Shadow Dragon in the blink of an eye.