Spock is a fictional character in the Star Trek media franchise. First portrayed by Leonard Nimoy in the original Star Trek series, Spock also appears in the animated Star Trek series, two episodes of Star Trek: The Next Generation, seven of the Star Trek feature films, and numerous Star Trek books, comics, and video games. In the 2009 film Star Trek, Nimoy reprised his role alongside Zachary Quinto, who played a younger, alternate-timeline version of the character, with Jacob Kogan playing Spock as a child.
Spock serves aboard the starship Enterprise, serving as science officer and first officer, and later as commanding officer of two iterations of the vessel. Spock's mixed human-Vulcan heritage serves as an important plot element in many of the character's appearances. Along with James T. Kirk and Leonard McCoy, he is one of the three central characters in the original Star Trek series and its films. After retiring from Starfleet, Spock serves as a Federation ambassador, contributing toward the détente between the Federation and the Klingon Empire. In his later years, he serves as Federation ambassador to the Romulan Empire and becomes involved in the ill-fated attempt to save Romulus from a supernova.
Spock did not originally have the logical manner which would become associated with the character, this instead being a trait of the character Number One (Majel Barrett). However, Number One was dropped in developing the second pilot, "Where No Man Has Gone Before" (1966). This episode presents a more fully formed Spock, with his trademark logic. Nimoy liked the character's newly logical nature, observing the character is "struggling to maintain a Vulcan attitude, a Vulcan philosophical posture and a Vulcan logic, opposing what was fighting him internally, which was human emotion". Spock's behavior has been described as representing, in part, a type of normative judgment. Spock's Vulcan salute references a sacred hand position used by the ancient Jewish priestly class. Desilu vice president Herbert Solow believes Nimoy was the key contributor to the character's depiction. Nimoy recalled, "As a Jew from Catholic Boston, I understood what it was like to feel alienated, apart from the mainstream...There were a number of values in 'Star Trek' that I felt very comfortable with as a Jew".