Reptile

### Original Timeline

During Shao Kahn's invasion of Earthrealm, he promised Reptile that he would restore his race and release Zaterra from Outworld control if he could accept a special assignment. Reptile accepted, and was dispatched (along with the mysterious female ninja Jade) to find and kill the rogue princess Kitana. Jade, however, betrays Reptile and assists Kitana (along with the warriors of Earthrealm) in Shao Kahn's defeat. Reptile was captured and exiled to the Netherrealm.

Long-time separation from his race caused Reptile to start reverting to a reptilian appearance. Escaping from the Netherrealm and losing his mind, Reptile begins committing genocide against several species in the realms. He was then recruited by the rogue Elder God Shinnok in his war against Raiden's forces of Light. After Shinnok's defeat, Reptile (along with spectre Noob Saibot) learned that Shao Kahn was still alive and returns to his service.

With the forces of Edenia (led by Kitana and Goro) waging war with the forces of Outworld, Shao Kahn sent Reptile to enlist the help of Shang Tsung. However, Reptile overhears the sorcerors Shang Tsung and Quan Chi plotting to assassinate Shao Kahn. As he rushed to warn his master, he was approached by the vampire Nitara, who revealed knowledge of Reptile's race, showed Reptile the location of Kitana's secret base, and offered him an ancient artifact of his people, the Kirehashi Blade. This, however, turned out to be a distraction, as Reptile returns to Shao Kahn's palace to find what he believed to be Kahn's corpse.

Reptile, having no master, wandered the Outworld wastelands directionless until he encounters Nitara a second time. He swears his allegiance to her, unaware that he was being manipulated into her plan to free her realm from Outworld's domination. She tricks him into damaging the device that allowed Cyrax to travel between realms, leaving the cyborg dependent on her. After realizing after some time that Nitara distracted him from Shao Kahn's assassination, Reptile went to confront Nitara and Cyrax, but found only the incubating egg of the Dragon King Onaga. The embryo pulses and fires a beam of white light at Reptile, transforming him to a hulkish beast while replacing his soul with Onaga's.

After Onaga's defeat, a humanoid form of Reptile myseriously appears with Reptile's soul. He allies himself with the Red Dragon clan, posibly seeing this alliance as an opportunity to clone and repopulate his race. However, he is defeated by Taven and is later killed in the Battle of Armageddon.

### Alternate Timeline

After Shao Kahn's destruction in the timeline influenced by Raiden's visions, Reptile ended up being an underling to Kotal Kahn and helps him usurp Mileena to become the new emperor of Outworld.

### New Era Timeline

In Liu Kang's reforged timeline, the Zaterrans are no longer near-extinct due to their realm no longer being conquered. Thus, Reptile was not planned to be an underling to an evil force. However, his unique ability to shapeshift between his human and reptilian form makes him an outcast among his people, and he leaves to search for a better life elsewhere on Outworld. He joins a traveling circus, but later becomes an unwilling servant for Shang Tsung, who took his family hostage.

When a trio of Earthrealm's champions, along with the Tarkatan Baraka, became jailed within Shang Tsung's Flesh Pits, Reptile was revealed to be their jailer. Baraka breaks out and defeats Reptile, but spares him. Reptile then joins the troupe after Shang Tsung reveals that he killed Reptile's family long ago. He uses his stealth to help them escape capture by General Shao's forces.

He later becomes Emperess Mileena's emissary to the Zaterrans, and discovers through official records that his unique shapeshifting mutation was actually common, but those who had it were killed by the Zaterran government in a barbaric policy to keep it from spreading.