Nightwolf (played by Litefoot) appears in Mortal Kombat: Annihilation as the one who teaches Liu Kang how to use his Animality and telling him that he has to pass three tests in order to beat Shao Kahn (only one test, Courage, is shown, however). Other than striking Liu Kang unconscious, he never really fights, though he is shown transforming back from his wolf form (introduced in Mortal Kombat 3 and implied by his name). After he strikes Liu, he is shown sitting at a campfire in Liu's dream.
In Mortal Kombat: Defenders of the Realm, Nightwolf (voiced by Tod Thawley) served to offer both spiritual and technical help, having experience with computer technology. He only fought a few times, spending most of his time back at base monitoring the Earthrealm looking for dimensional rips. Nightwolf had a pet wolf named Kiva, who could merge with Nightwolf to increase his power.