Goten

Goten (孫悟天, Son Goten) is a protagonist in the Dragon Ballmanga and the animes Dragon Ball Z and Dragon Ball GT. He is the second and last child of the main protagonist of the Dragon Ball series, Goku, and his wife, Chi-Chi, making him a Saiyanand Human hybrid. Goten was created in the series to replace Goku as Akira Toriyama wanted to retire Goku from the series, allowing Gohan to take command. However, Toriyama was forced to bring Goku back when the fans disapproved of the decision to replace him. Goten is Gohan's younger brother, andTrunks' best friend. 

Goten's appearance is very similar to Goku's childhood look, including messy, unkempt hair and a playful face. He also wears a similar gi to Goku's, minus the kame symbol, in the Majin Buu Arc. His appearance drastically changes as he grows older, resembling his brother Gohan more than his father as a teenager; he has the same long messy hair as Gohan at a younger age. Towards the end of Dragon Ball Z, Goten is seen with a shaggier hairstyle. Goten also shares the typical Saiyan appetite like his father and his brother. In Dragon Ball GT, his hairstyle becomes spiky, straight, and tilted.

Goten is the second son of Chi-Chi and Goku, and younger brother to Gohan. Goten is born nine months after the defeat of Cell in the Cell Games Saga. As Goku dies during the Cell Games, while Chi-Chi is pregnant, Goten does not meet his father Goku until he reaches the age of seven. Goten is not pushed in school as much as Gohan is, and instead is trained in martial arts by Chi-Chi. The reasons for this are never fully explained, but it seems to have something to do with Goku's death.
Goten is incredibly strong as a child, far stronger than either Goku or Gohan ever were at his age. Chi-Chi first discovers that Goten can become a Super Saiyanat only seven years old (the Dragon Ball Z: Buu's Fury video game manual says that he was only three years old when he first went Super Saiyan), and he looks almost exactly like Goku when he first transformed into a Super Saiyan. Goten transforming into a Super Saiyan made him the youngest Super Saiyan ever at that point. When Gohan asks how his transformation occurred, Goten said that he was learning Martial Arts from his mom and accidentally turned into a Super Saiyan, so she told him never to transform again. The ease at which he does so has been a matter of controversy, seeing as it took years for Goku, Vegeta, and, to a lesser extent, Gohan to obtain and master the technique. Whatever the reason, Goten displays exceptional power at a young age, rapidly increasing his strength. During Goten's childhood he is good friends with Bulma and Vegeta's son Trunks, who he would have "fight games" with. This serves to increase their respective strength significantly, compared to the other Human-Saiyan hybrids that are seen at that age, and both became a Super Saiyan at a young age.