Sub-Zero, real name Kuai Liang (奎良, and formerly known as Tundra), is a Lin Kuei assassin in the Mortal Kombat fighting game series. He is the younger brother of Noob Saibot, who was the original Sub-Zero in the first Mortal Kombat game. The younger Sub-Zero made his debut in Mortal Kombat II. In one form or another, Sub-Zero has appeared in every generation of Mortal Kombat games as a playable character. His Street Fighter rival is Abel.
Sub-Zero is also descended from Cryomancers: an Outworld race possessing the ability to generate and control the powers of ice, although both of them were born in Earthrealm. Kuai Liang bears a scar on his right eye, which he received between the events of MKII-MK3. However, as of Deception, the scar has faded away, possibly because of the effects of his Dragon Medallion.
His Icy powers give him a decent advantage over normal opponents.