Son Goku (孫 悟空, Son Gokū?, addressed only as Goku in most English adaptations) is a fictional character from the Dragon Ball universe created by Akira Toriyama as the main protagonist for the media franchise. He is loosely based on Sun Wukong, a central character in Journey to the West, however, Toriyama changed some of his characteristics to be more original. Goku is introduced as an odd, monkey-tailed boy who practices martial arts and possesses superhuman strength. As the story unfolds, he is actually revealed to be from a fictional race of extraterrestrials called Saiyans, said to be the strongest warriors within the fictional universe. Goku also made cameo appearances in Toriyama's self-parody series Neko Majin Z and also starred in all the films, specials and video games from the series.

Source: Wikipedia