Chameleon

Chameleon is a ninja who utilizes camouflage during fights in the Mortal Kombat fighting game series. He made his debut in the Sega Genesis version of Ultimate Mortal Kombat 3 (through a Game Genie). He also appeared as a hidden character in the PC, PlayStation, and Sega Saturn versions of Mortal Kombat Trilogy and as a playable character in Mortal Kombat: Armageddon.

About Chameleon
Chameleon first debuted in the PlayStation, Sega Saturn, and PC versions of Mortal Kombat Trilogy as a male ninja with partial transparency that changed color. In the Nintendo 64 version, he was replaced by Khameleon, a female counterpart who is actually an entirely separate character. There was initially little information about Chameleon as he had no storyline or game ending. All that was known about him is garnered from the hidden option to fight him (available upon beating the game), in which he is referred to as "one of Shao Kahn's deadliest warriors". He later returned in Mortal Kombat: Armageddon with a completely new design and a backstory.

Storyline
Chameleon is likely a part of the Saurian race, of which Reptile and Khameleon are members. This has never been conclusively stated in any of the games and is purely speculation on the part of the fans at this point due to his reptilian name, green blood, and the reptilian titles of his special moves in Armageddon. He has even shared similar features with Khameleon in both of their appearances, furthering the speculation.

If he IS a Saurian, that would mean that Reptile is not the last living male of his species, which had been previously stated in Khameleon's biography screen. However, the release of Armageddon did not address this issue.

In Mortal Kombat: Armageddon, he is finally given a rather vague backstory, stating that he had been present at events dating all the way back to Liu Kang's victory in the first Mortal Kombat tournament, constantly remaining hidden in the shadows and biding his time while watching the events unfold. He's not seen participating in the final Battle of Armageddon, so his fate is unsure, but he's supposed to be dead like all other kombatants except Shao Kahn, Raiden, Shinnok, Taven and Liu Kang (spirit).