G-Man (Half-Life) refers to simply as his "employers". His mysterious nature has made him an icon of the "Half-Life" series, with his identity and motives remaining almost completely unexplained. The G-Man's name comes from "G-Man", an American colloquialism meaning "Government Man". However, within the "Half-Life" games, he is identified by this name only in the program code and the multiplayer profile menu as a default name option, not within the story itself; his name is derived from his "Half-Life" model and entity name and has since been reused in subsequent games of the series. His name has been confirmed and he has
G. Callen G. Callen G. Callen (born: Grisha Alekandrovich Nikolaev) is a fictional character in the show "" portrayed by Chris O'Donnell. He is an NCIS Special Agent in Charge, and the senior agent assigned to the Office of Special Projects. O'Donnell made his first appearance during "NCIS" sixth season episode "Legend (Part 1)". Before working at NCIS, Callen previously worked for the CIA, DEA and FBI. Several episodes across the seasons reference his stint with the Agency and in seasons one and two, it is revealed that whilst with the CIA, Callen worked alongside recurring "NCIS" character, Trent Kort (David Dayan