These beings were typically skeletal looking creatures who were forever to be tormented within their fiery homeworld. Some were capable of ripping apart bloody chunks from their body and throw them at their enemies as a form of grenade attack. When encountering living creatures, the Undead often converged on fresh meat in order to devour it. Typically, they ambushed prey by suddenly emerging from the ground.
Liu Kang and Kung Lao encountered and defended themselves against numerous undead enemies in the Living Forest, the Soul Tombs, the Sea of Blood in the Wastelands of Outworld, and even the Netherrealm itself.Taven was forced to fight numerous undead during his trek through the Netherrealm.
- Bloody Skeletons
- Decayed Warriors
- Putrid Corpses
- Undead Revenants
Numerous characters in the game series are either undead or have been undead at some point.
- Scorpion is one of the main undead characters in the series. As a ninja spectre doomed to roam the realms looking for vengeance, he rises from Hell time and time again. In Mortal Kombat X, he is restored to life.
- In the original timeline, Liu Kang was murdered at the hands of Shang Tsung, only to be brought back from the dead by Raiden as a zombie and as an enforcer. In the alternative timeline, Liu Kang is revived as a revenant by Quan Chi after he is accidentally killed in a conflict with Raiden.
- In the alternative timeline, Kung Lao was killed by Shao Kahn, and was resurrected by Quan Chi as an undead.
- In the alternative timeline, Kitana, Jade, Jax, Smoke, Kabal, Stryker, and Cyber Sub-Zero were killed by a corrupted and supercharged Sindel single-handedly, who was powered by the souls that made up Shang Tsung. Nightwolf later sacrificed himself to kill the Edenian queen. All were resurrected as undead warriors to serve their new master, Quan Chi. In Mortal Kombat X, Jax and Sub-Zero are restored to life, but the others remain trapped in the Netherrealm's forces after Scorpion killed Quan Chi and Cassie Cage defeated a corrupted Shinnok, with Kitana and Liu Kang later becoming the Netherrealm's rulers following Shinnok's defeat.
- Freddy Krueger, a DLC character from Mortal Kombat (2011), was burned alive in his boiler room by the parents of Springwood throwing Molotov cocktails, but was revived by three dream demons and was given the ability to invade people's dreams and kill them.
- Jason Voorhees, a DLC guest character from Mortal Kombat X, was drowned in Crystal Lake when he was a little boy, and after he was resurrected into a genuine revenant, he avenges his mother's death by killing several people who were responsible for her death, then later makes a career in killing teenagers and other unfortunate victims, and even clashed with Krueger.
Known Undead Characters
- Noob Saibot (Former Human/Cryomancer)
- Liu Kang (Former Human)
- Scorpion (Former Human, 1st Timeline)
- Kabal (Former Human, 2nd Timeline)
- Kung Lao (Former Human, 2nd Timeline)
- Sindel (Former Edenian, 2nd Timeline)
- Kitana (Former Edenian, 2nd Timeline)
- Jade (Former Edenian, 2nd Timeline)
- Smoke (Former Human/Enenra, 2nd Timeline)
- Stryker (Former Human, 2nd Timeline)
- Nightwolf (Former Human, 2nd Timeline)
- Freddy Krueger (Former Human)
- Jason Voorhees (Former Human)