Goku Black, usually referred to as Black, is the main antagonist of the Future Trunks Saga of Dragon Ball Super. His true identity is the original present Zamasu from the unaltered main timeline, in which he stole the body of the original present Goku and sought to destroy all mortals alongside Future Zamasu. He was given the name "Goku Black" by Future Bulma when he initially referred to himself as Son Goku.

In the manga, he and the Zamasu from the altered main timeline were originally the same entity. However, Beerus destroying the Zamasu in the past split the timeline. In the anime, Black's existence is the result of a causal loop in which had no beginning or end but was a series of events that led Black's creation. Beginning when Future Trunks traveled back before the original future events were in motion and when Goku Black fought Goku, this caused a series of events that led to the destruction of Zamasu, causing the main timeline to split into two, creating an identical timeline. Except in the unaltered, original present (Main) timeline, Black succeeded in his initial dark deed and none of the Dragon Team was aware of his plans and actions. Thus, the Zamasu who became Goku Black is - or was - the exact same individual, and has all of the same history as the Zamasu from the altered present timeline prior to his destruction at Beerus' hand. Due to the powers of the Time Ring, the death of the present Zamasu from the altered main timeline due to Beerus did not affect him.