As a child, he was a replica of his dad’s childhood look. They both possessed a playful face and also, rough and untidy hair. It was even confirmed by other characters like King Piccolo, Freiza, Broly and Cell who all at different occasions, confirmed Goten as a resemblance to his father, Goku.
As he approached teen, he looked more like his brother than Goku with some shabby hair just as Gohan. His hairstyle was changed at the end of Dragon Ball Z so that he wouldn’t be mistaken for his dad.
Just as his dad, Goten is a naïve and kind-hearted character and to an extent, mischievous. His playful attitude is linked to the influence of Trunks, his best friend. He always bows before fighting an opponent that shows his good manners, and he views his elder brother Gohan as a role model.
Goten loves wild animals, bug-catching and play-fighting. He possesses a keen appetite for food and food was always used to wake him up. His favorite meal is Strawberry daifuku and pocky sticks. As a teenager, he chose to live an average life worrying more about bikes and girls than fighting.
As a child, he exhibited a kind of strength that was never seen in his father and elder brother, and it was discovered that he could become a Super Saiyan at the tender age of seven. He later became the youngest ever Super Saiyan at the time he was transformed. He was highly talented in martial arts, and he learned faster than his dad and elder brother.
When he heard that his father would return to earth for the 25th World Martial Arts Tournament, Goten trained hard with his elder brother, Gohan. His exceptional strength was discovered by Gohan when he could not dodge the rocks thrown at him by Goten during the training. Gohan alongside his friend (and later wife) Videl taught Goten the art of fighting and flying.
He was shy when he first saw his dad, but they later played airplane together. He participated at the Junior category of the World Martial Arts Tournament where he defeated Ikose and made it to the final against his best friend Trunks. Before the final, they promised not to transform to Super Saiyans but Trunks had to break his promise to defeat Goten. They however disguised themselves as Mighty Mask to participate in the Adult category.