Sub-Zero is a video game character from the Mortal Kombat series and one of the original characters in the first Mortal Kombat game. The character made a return appearance in Mortal Kombat II, in which it was revealed that the original Sub-Zero had died during the events of the first game and was replaced by his younger brother. In susbquent games, the younger brother remained as Sub-Zero, while the elder brother became Noob Saibot.