Dragon Ball Z
Goten is the son of Goku and Chi Chi and the little brother of Gohan. His best friend is 8-year-old Trunks. He is introduced to us during the Buu Saga at age 7. He is, like his brother, overprotected by his mother. But unlike Gohan, Chi-Chi has taken the liberty of training him since Goku has been killed by Cell. Gohan offers to take Goten to train for the upcoming tournament and is surprised to find that Goten can already transform into a Super Saiyan. Because Gohan has been slacking in his training, Goten is almost stronger than his brother at this point in time.
At the tournament, Goten meets his father Goku for the first time. He is wary of him, but grows to really like him in no time. The child's division of the tournament proves to be no real problem for Trunks and Goten until the final match where they fight one another. Before going out, they make a deal not to transform during the fight. The battle starts out and they are equally matched. Goten, forgetting the deal, transforms. Trunks reminds him and returns to normal. The fight continues and Trunks eventually knocks Goten out of the arena, transforming himself. Trunks promises to give Goten three of his toys to make up for winning.
They then dress up as The Masked Fighter to compete in the adult tournament. They make it to Android 18, but then are disqualified because 18 destroyed their costume.
Goten and Trunks go off to help Vegeta fight Majin Buu. The boys were knocked out by Vegeta before he sacrificed himself to destroy Buu.
At Kami's Lookout, Goten is informed that Gohan has ben killed by Buu. Goten, upset, begins to cry and is angry at Goku for not saving his brother. Gou explains that there is no time for crying and they need focus their anger and pain into the Fusion Technique, which will merge their powers into one being for a certain amount of time. After showing the boys Super Saiyan 3, Goku leaves for the Afterlife and leaves Piccolo in charge of their training.
Buu eventually finds them and the boys run into the Hyperbolic Time Chamber, speeding up time and allowing them to perfect the technique. Buu, ready to fight them, charges into the chamber. He finds Gotenks, the fused warrior. They fight, and Gotenks pretends to lose. Piccolo, afraid, blows up the door to the outside world. Buu then creates a door out. Gotenks, upset with Piccolo for ruining everything, transforms to Super Saiyan 3 and creates a door as well.
After a quick fight, Trunks and Goten separate and are absorbed by Buu, improving his strength. They are saved by Goku and Vegeta, but are killed soon after by Earth's destruction. They are revived by the Dragon Balls after Buu is killed.
Dragon Ball GT
Goten is a minor character in GT. He is the uncle of Pan, and is shown with a girlfriend, Valese. He lends a hand in fighting major enemies, but does not defeat any of them.
Goten is the youngest Super Saiyan ever in all of Dragon Ball Z and Dragon Ball GT. As the youngest to achieve the Super Saiyan form he has perfect control and mastery over it and can use it as though it was his normal base form. Goten possibly achieved this form during a training session with Chi-Chi when she kicked which probably angered him slightly as he then transformed much to Chi-Chi's shock and knocked her down with his own attack and she then never told him to transform into a Super Saiyan again calling it a "monster" making Goten think that transforming into a Super Saiyan made him a monster or that when he is a Super Saiyan he is a monster, however, Gohan later explains what Chi-Chi meant and that a Super Saiyan is not a monster. However it is unknown if Goten was restraining himself during his training session with Chi-Chi and that he transformed because he realized his mother was not to be taken lightly or was not a push over and it was not the first time he achieved the Super Saiyan and was simply the first time it was seen or it was possibly genuinely the first time he had ever transformed into a Super Saiyan however it could be that it was simply the first time it was every seen rather than the first time he achieved the form.
In this form Goten's base power increases 50x his original power level and it is stated that in this form he is much more powerful than Frieza using 100% of his power and he is also more powerful than the Super Saiyan Goku that fought Frieza on Namek, his power and speed increase greatly in this form and even Gohan is surprised at Goten's power when he first witnessed Goten transform, also Goku was shocked after he witnessed both Trunks and Goten transform into Super Saiyans as he stated that they should be careful or they could be surpassed by the young Super Saiyans hinting that they are very powerful or it could have simply been a joke and a surprising reaction by Goku. As a Super Saiyan Goten is stronger than android 18 as shown in the movie Bio Broly when 18 can't hurt Broly but Goten can.
In this form Goten's appearance changes drastically as he gains a slight increase in muscle, his hair turns blonde, becomes straighter and spikier, his hair becomes longer and stands upwards on end and there are less bangs of hair hanging over his forehead, his irises turn green, his skin tone becomes lighter and a flame-like golden energy is formed around his body. Goten has perfect control over his Super Saiyan form and can easily maintain it auralessly.
Powers & Abilities
Superhuman Strength: Goten being a Saiyan/Human hybrid is physically stronger than the average untrained Saiyan and was able to achieve the Super Saiyan form without any effort at a very young age and is functionally the youngest Super Saiyan and the youngest to ever achieve the Super Saiyan form. Goten's physical superhuman strength is far greater than any human in the universe and greater than that of an average Saiyan as he has shown to be strong enough to knock a large dinosaur unconsciousness with a single punch whilst in his normal base form without any effort and extreme ease, he easily lifted a possibly 2 ton dinosaur with no physical effort with a single arm as a child in his base form and has even surprised Gohan during their training session. It has been stated several times that Goten is more powerful than Frieza and was more powerful than Super Saiyan Goku during his fight against Frieza's 100% power state. It is unknown how many tons Goten can lift but it is highly likely that in his Super Saiyan form he can lift well over 40 tons because Goku has been seen training with 40 tons in total (10 tons on each arm and leg) in 10 times gravity making it 400 tons with no known upper limit.
Superhuman Speed: Goten's Saiyan/Human hybrid physiology grants him vast amounts of superhuman speed. Goten reacts and moves at superhuman speed. He has shown the ability to run faster than moving cars with minimum or no effort and can functionally fly at or possibly beyond the speed of sound (770 mph). Goten has been shown dodging lightning fast attacks that cannot be seen by the human eye and he can move so fast that he can seemingly disappear and reappear in another location.
Superhuman Durability: Goten's Saiyan/Human hybrid physiology grants him super human durability however the exact level of which is unknown. Goten has survived being knocked through very hard rock formations, he has withstood powerful energy blasts and held his own for a while against Super Saiyan Broly (not Legendary Super Saiyan Broly) and Bio Broly. Goten has withstood hits from Super Saiyan Gohan without any visible physical damage and can withstand falls from great heights.
Energy Manipulation: Goten like all Saiyans can manipulate energy however he mostly or almost manipulates ki for various purposes such as energy blasts, energy balls, energy waves etc. Goten can manipulate ki energy to create a powerful energy blast or energy wave called "The Kamehameha Wave" which he mispronounces "Kamekameha" due to the slip of the tongue which he first demonstrated during the World Tournament during his battle with Trunks. Goten can create energy balls as well and has shown the ability to create an explosive energy ball similar to The Spirit Bomb however he does not ask for energy and uses his own, this ability is only used once and creates immense destruction upon its devastating impact. Goten can also unleash an explosive wave of energy which can be used to knock opponents away or down. Goten can gather the ki energy in his environment to increase and or enhance and or augment his power and as he increases his power a flame-like aura is formed around his body and begins to flicker as the energy shifts when he increases it. Goten can also concentrate the energy into separate places of his body such as his fists to cause more damage when he delivers punches this attack is called an "Energy-Enhanced Strike", Goten can also channel ki energy through his body to increase or augment his physical strength.
Radar Sense: Goten has the ability to sense the ki energy of other beings and can locate them by following the energy trail they leave behind as he tracks their energy signature however it is unknown if he can sense and track the remnants of energy signatures.
Flight: Goten has the natural ability of flight however he was unaware of it until it was taught to him as all Saiyans have the natural ability of flight. Goten is able to fly extremely fast and has great control over his ability of flight as he can hover, move swiftly through the air performing aerobatic movements, levitate, spin swiftly through the air while maintaining, increasing or decreasing spin while maintaining areal balance and coordination. It is unknown if Goten can fly well in high atmospheric intense and harsh pressures, temperatures and environments however it is noted that Goten can perfectly maintain flight while battling an opponent.
Superhuman Agility: Goten's Saiyan/Human hybrid physiology grants him superhuman agility, bodily coordination and balance greater than that of any human in the universe. Goten can perform complicated acrobatic movements while perfectly maintaining balance without effort and has on occasion performed circus-like movements during battle as he dodged and easily evaded very fast attacks that are unseen by the human eye.
Superhuman Stamina: Goten's Saiyan/Human hybrid physiology produces less fatigue poisons than any human in the universe. Goten can engage in intense physical activity for days before his body begins the production of fatigue toxins and it impales his blood and body tiring him in the process.
Unarmed Combat: Goten has some degree of experience and training in hand to hand combat and is an expert martial artist surprising even Goku and Gohan's expectations. Goten was trained by Goku, Gohan, Chi-Chi, Piccolo and trains with Trunks.