Joaquin was a genetically engineered augment from Earth's 20th century, a follower of Khan Noonien Singh and survivor of the Eugenics Wars. Joaquin escaped Earth aboard the SS Botany Bay.
In 2267, the Botany Bay was discovered by the USS Enterprise, where he was one of the 72 surviving members of Khans' original group of 84. (TOS: "Space Seed") In Greg Cox's novels about the Eugenics Wars, Joaquin was a faithful bodyguard of Khan and the father of Joachim, who was one of Khan's crew in Star Trek II: The Wrath of Khan.