Goku's great great grandson who shares his name. He appears at the end of Dragonball GT and is the protagonist of the last Dragonball movie.
Goku Jr. is Goku's great-great grandson ( Pan's grandson). Just like his great grandfather Gohan at a young age, Goku Jr. is very timid, and would run away from situations like being bullied. He would not do anything to retrieve what was stolen from him. He is seen once at the end of Dragon Ball GT, fighting in what may be the 64th World Martial Arts Tournament against a distant descendant of Vegeta's, Vegeta Jr. He also appears in the final Dragon Ball Special, A Hero's Legacy, in which he meets Goku. He is 1/16th Saiyan, and has the power to become a Super Saiyan. His ability to turn Super Saiyan raises much confusion because earlier in the series, it states that even a 1/4th Saiyan can't go Super Saiyan due to having diminished Saiyan blood (this is the reason why Pan is not able to go Super Saiyan). But then, Toriyama also indicated that Pan might have gone Super Saiyan, but "did not have a reason to" despite the fact that Trunks and Goten were able to go Super Saiyan during peaceful times, Although the whole confusion behind Pan not turning into a super saiyan coul be due to the difficulty in designing a female super saiyan since most of the characteristics involving super Saiyan are mostly seen by males.
His gi resembles Goku's, with the exception of having blue pants and a teal shirt underneath his vest (though in the finale of Dragon Ball GT, he wore Goku's preserved, ancient gi). Goku Jr.'s hair is in the same style, shape and form of Goku's. He has black hair and dark blue eyes. His headband is red, which makes it resemble the headband his great great great grandfather Bardock wore before he took on Frieza to defend the Saiyan Race from eradication. His skin color resembles Gohan's milky white or very lightly tanned. The only notable difference between him and Goku and/or Goten is his face, which more resembles his mother's side of the family. In A Hero's Legacy his gi sort of resembles the one Goku wore in the Androids Saga to the Kid Buu Saga with the exception of it being blue instead of orange. It is highly likely that after Goku Jr.'s fight with Vegeta Jr. both of them later became the protectors of Earth and might have had a rivalry similiar to that of Goku and Vegeta's, when Vegeta Jr. witnesses Goku Jr. transform into a Super Saiyan he immediately comments on him making it clear that neither both of them are aware of the transformation's name and that they are of Saiyan heritage.
Goku Jr. has displayed numerous powers such as superhuman strength, superhuman speed, flight, superhuman stamina, superhuman agility and superhuman durability. It is also believed that Goku Jr. is able to manipulate energy for various purposes such as energy blasts and energy balls, Goku Jr. superhuman strength is comparable or on par with that of Vegeta Jr. and both of them have displayed the ability to transform into a Super Saiyan however at first Goku Jr. is unable to maintain the form and becomes extremely exhausted however later when he enters the tournament and fights Vegeta Jr. he seems to have mastered the form as he fights Vegeta Jr. in and both of them are in their Super Saiyan forms fighting each other without a sign of exhaustion, his Super Saiyan transformation increases his overall power dramatically and his hair turns blonde and it stand more upright with less bangs of hair hanging over his forehead and his hair in his Super Saiyan form is nearly identical to that of Goku's, his muscular mass increases and his eyes become green.
Goku Jr. first obtained this form after seeing his bear friends almost being killed by the Demon King. Upon his transformation, he easily defeated the Demon King and scared off his servants, but he had no memories of ever transforming or defeating the Demon King Yao. However, by the time he fought Vegeta Jr., he had learned to transform at will.
Goku Jr is a descendant of the legend that is goku. Goku Jr has fought many villains on Earth and is just like his ancestor Goku, in fact Goku Jr even resembles goku