Japanese Names: Gokū Burakku (ゴクウブラック), Zamasu (ザマス)Name Pun: Heaven and Emptiness, to be, to existFUNimation Name: Goku Black, ZamasuSilver Shenron Name: Goku Black, ZamasuOther Names: Son GokuRace: Saiyan (Goku's body), Shinjin (Zamasu's mind)Height: 175 cm (adult)Weight: 62 kg (adult) Birth Year: Age 737 (Goku's body)Death Year: Age 796 (erased from existence)Hobbies: finding strong opponents and fighting with them (Goku's body)Favorite Food: will eat anything (Goku's body)Favorite Vehicle: Kinto-un (Goku's body)First Appears: Chapter 014 [DBS Manga], Episode 047 [Anime, DBS]Appearances: DBZ, DBSSeiyuu: Masako NozawaVoice Actor: Sean Schemmel
Prior to switching bodies with Son Goku, Zamasu was the former Dai-Kaio of Universe 10 and the Kaioshin apprentice of Gowasu as his successor, based on his battle talent. He was a witness of the countless wars done by humans. Zamasu was happy about it, and promised to do his best for universal peace. This incarnation of Zamasu was not destroyed by Beerus in this unaltered timeline.
Because of his is prodigious fighting skill and his continuous distrust of mortals and growing dismay of the Kais' passive and indirect influence of the universe's development, he ultimately rejected his teachings and went rogue, developing his Project Zero Mortals. To which, his ultimate goal became to annihilate all mortals in a specific timeline, then build up from there, to purge all mortals from all of existence with it, making the multiverse in his perspective a "beautiful utopia", rid of the mortals who ruin it. Requiring a Time Ring for his plans, Zamasu killed Gowasu and took his Potara earring to become a Kaioshin, so he could wield the Time Ring.
Afterwards, he used these items to gather and use the Super Dragon Balls to switch his body with Goku and killed the Goku in Zamasu's body, Chi-Chi and Goten; and traveled to Mirai Trunks' timeline and allied with his future counterpart there.This Zamasu began the main stage of his Zero Mortals Plan, terminating the Kaioshins, therefore the Daikaioshins, annihilated several mortal planets in the Universes, and destroyed Earth's civilization, effectively becoming known as Goku Black. Black fought Mirai Trunks numerous times, aiming to gain full control over Goku's body. Eventually, Future Trunks fled back in time to get help from the heroes of the past. Vegeta Blue vs Black and Gold Goku Black fights Vegeta.
Goku and Vegeta return to the future with Mirai Trunks and Vegeta is the one to battle him, Black uses his Super Saiyan form to battle Super Saiyan 2 Vegeta, but proves to be outmatched., Vegeta turns into Super Saiyan Blue and tells Black to use the form too, but Black reveals that he cannot and so he is beaten back by Vegeta. At the same time as Super Saiyan Blue Vegeta's initial battle with Super Saiyan Rose Goku Black is coming to a close in Future Trunks' timeline, Beerus went to visit Universe 10 and destroys Zamasu; splitting the timeline - thus erasing the original future from happening and creating a split timeline.
However, the Zamasu who had succeeded in the original present timeline was still alive and carried on, eventually learning of his past self's death from Goku and Vegeta in their first trip to the future in the manga. Ultimately, however, this Zamasu met the same fate as Present Zamasu, erased from existence - albeit from Future Zeno.