It's almost that time! MKX is upon us in just one week! MK started the secret fighter trend in fighting games, IIRC. And as usual, I believe we will be in for some surprises when it comes to secret and unlockable fighters. I have stayed in the dark mostly about the new MK's roster, but without a doubt there will be secret fighters we fight against, and not all of them may be selectable within the game, normally (as per MK tradition). So, here's a refresher on what we have had thus far (and what became of them);
Mortal Kombat
Reptile - The progenitor. Not selectable, but a secret fighter one could face at the bottom of the Pit stage. He used both Sub Zero's and Scorpion's moveset.
Mortal Kombat II
Smoke, Jade, and Noob Saibot - Continuing with having characters you can not normally face unless certain specific conditions are met during normal play, these three were introduced. Also, all palette swaps. Like Reptile before them (who is now a normally selectable character), they used moves from the other "ninja's", and had better attributes, like faster walking speeds. You fight them in Goro's Lair from the original MK.
Mortal Kombat 3
Smoke, Noob Saibot - Now having been turned into a cyborg by his clan, Smoke is back as a secret fighter one could face, again. But for the first time in MK, you could enter a code to make him selectable character, accessible on the character select screen. For the most part, he had his own unique moves that resembled his moveset (Scorpions in actuality) from MKII. Noob Saibot was a fighter one could only fight, and due to there not being any actual "ninja's" (outside of the now unmasked Sub-Zero), Midway used Kano's silhouette as a fill in due to it resembling the outfit of the previously shown MK ninjas. You fight him in Noob's Dorfen, which is the area in the back of the Balcony.
Ultimate Mortal Kombat 3
Human Smoke, Classic Sub-Zero, Mileena, Ermac, Noob Saibot, Rain - It was obvious a demand for traditional "MK ninjas" was in effect, and this game had them in spades. Smoke is once again a secret character that can be unlocked, this version hearkens back to his pre-MK3 days. Plays like Scorpion, and is faster. Sub-Zero's new look didn't gel well with most fans, so his original mask n' all appearance was brought back. Mileena has her own original moveset, and is selectable via code as well. Ermac is a new character, based on a rumor dating back to the original MK arcade game. In the attract mode, you could briefly see another ninja named Rain, who was meant to be a red-herring type character, but for whatever reason was made into a fully playable character, along with a proper ninja version of Noob Saibot in the home versions of UMK3.
Mortal Kombat Trilogy
Chameleon, Khameleon, Human Smoke - In the PSX version of this release, a male ninja who switches between all the ninjas in the game's movset. Can be selected via a code. In the N64 game, the roster was not exactly the same as the larger PSX's roster. Instead of the male ninja, we get a different character named "Khameleon", who functions similarly to her counterpart. We also get Human Smoke again, who plays a little differently from his UMK3 version. He is normally selectable in the PSX version, however.
Mortal Kombat 4
Meat, Noob Saibot, Goro - Meat is a model glitch, and a secret playable character. Beating the game as a "meat" character in the arcade game actually crashes/resets the game. Noob was actually meant to be playable in the original arcade release, but it seems his model was altered slightly he became Reiko, a "new" character instead. He was brought back as intended as a secret character in the home ports. Goro is unlockable as well in the home ports.
Mortal Kombat Gold
Sektor, Noob Saibot, Goro - Both Noob Saibot (who now has a full fledged movelist) and Goro make a return as secret selectable characters. Meat is gone however, and in his place Sektor makes an appearance. While Cyrax's design changed a bit, Sektor looks most like their original MK3 era design.
Mortal Kombat: Deadly Alliance
Mokap, Blaze - Some of the most odd characters out of the bunch, we have Mokap and Blaze. Mokap (which is a play on "Motion Capture") is actually Carlos Pesina, brother to Daniel Pesina to played a host of characters in the first two Mortal Kombat games before being let go. He did all the motion capture for everyone in Deadly Alliance. Blaze is based on a rumor dating back to MKII about a character who was literally on fire in the distance on the Pit II stage being playable.
Mortal Kombat: Deception
Liu Kang - A nice secret kept until release, and the lone secret character of Deception. Liu Kang (who was executed in the intro of the previous entry) is back as a powerful undead warrior, controlled by the now Dark Rayden. Getting his is tricky, but the return is one of the strongest characters in the game.
Mortal Kombat: Armageddon
Taven, Daegon, Blaze, Meat - Back with a redesign, and a new moves at his disposal. Meat is now the sole unlockable secret character outside of Taven, Daegon, and Blaze (who play major roles in the story mode). Blaze had a massive redesign, and is the final boss of the game.
Mortal Kombat (2011)
Reptile, Smoke, Jade, Noob Saibot, Quan Chi, Cyber Sub-Zero - In a very nice homage to the original games, once again Reptile, Smoke, Jade, and Noob are secret fights. Quan Chi, and Cyber Sub-Zero (who instead of Smoke, fell victim to their clan's betrayal) are unlockable through story mode.
My favorite MK character is Noob (the OG Sub). Ed Boon is also a big fan of his, so I'm hoping he ends up in MKX. Even if he isn't playable.
Mortal Kombat
Reptile - The progenitor. Not selectable, but a secret fighter one could face at the bottom of the Pit stage. He used both Sub Zero's and Scorpion's moveset.
Mortal Kombat II
Smoke, Jade, and Noob Saibot - Continuing with having characters you can not normally face unless certain specific conditions are met during normal play, these three were introduced. Also, all palette swaps. Like Reptile before them (who is now a normally selectable character), they used moves from the other "ninja's", and had better attributes, like faster walking speeds. You fight them in Goro's Lair from the original MK.
Mortal Kombat 3
Smoke, Noob Saibot - Now having been turned into a cyborg by his clan, Smoke is back as a secret fighter one could face, again. But for the first time in MK, you could enter a code to make him selectable character, accessible on the character select screen. For the most part, he had his own unique moves that resembled his moveset (Scorpions in actuality) from MKII. Noob Saibot was a fighter one could only fight, and due to there not being any actual "ninja's" (outside of the now unmasked Sub-Zero), Midway used Kano's silhouette as a fill in due to it resembling the outfit of the previously shown MK ninjas. You fight him in Noob's Dorfen, which is the area in the back of the Balcony.
Ultimate Mortal Kombat 3
Human Smoke, Classic Sub-Zero, Mileena, Ermac, Noob Saibot, Rain - It was obvious a demand for traditional "MK ninjas" was in effect, and this game had them in spades. Smoke is once again a secret character that can be unlocked, this version hearkens back to his pre-MK3 days. Plays like Scorpion, and is faster. Sub-Zero's new look didn't gel well with most fans, so his original mask n' all appearance was brought back. Mileena has her own original moveset, and is selectable via code as well. Ermac is a new character, based on a rumor dating back to the original MK arcade game. In the attract mode, you could briefly see another ninja named Rain, who was meant to be a red-herring type character, but for whatever reason was made into a fully playable character, along with a proper ninja version of Noob Saibot in the home versions of UMK3.
Mortal Kombat Trilogy
Chameleon, Khameleon, Human Smoke - In the PSX version of this release, a male ninja who switches between all the ninjas in the game's movset. Can be selected via a code. In the N64 game, the roster was not exactly the same as the larger PSX's roster. Instead of the male ninja, we get a different character named "Khameleon", who functions similarly to her counterpart. We also get Human Smoke again, who plays a little differently from his UMK3 version. He is normally selectable in the PSX version, however.
Mortal Kombat 4
Meat, Noob Saibot, Goro - Meat is a model glitch, and a secret playable character. Beating the game as a "meat" character in the arcade game actually crashes/resets the game. Noob was actually meant to be playable in the original arcade release, but it seems his model was altered slightly he became Reiko, a "new" character instead. He was brought back as intended as a secret character in the home ports. Goro is unlockable as well in the home ports.
Mortal Kombat Gold
Sektor, Noob Saibot, Goro - Both Noob Saibot (who now has a full fledged movelist) and Goro make a return as secret selectable characters. Meat is gone however, and in his place Sektor makes an appearance. While Cyrax's design changed a bit, Sektor looks most like their original MK3 era design.
Mortal Kombat: Deadly Alliance
Mokap, Blaze - Some of the most odd characters out of the bunch, we have Mokap and Blaze. Mokap (which is a play on "Motion Capture") is actually Carlos Pesina, brother to Daniel Pesina to played a host of characters in the first two Mortal Kombat games before being let go. He did all the motion capture for everyone in Deadly Alliance. Blaze is based on a rumor dating back to MKII about a character who was literally on fire in the distance on the Pit II stage being playable.
Mortal Kombat: Deception
Liu Kang - A nice secret kept until release, and the lone secret character of Deception. Liu Kang (who was executed in the intro of the previous entry) is back as a powerful undead warrior, controlled by the now Dark Rayden. Getting his is tricky, but the return is one of the strongest characters in the game.
Mortal Kombat: Armageddon
Taven, Daegon, Blaze, Meat - Back with a redesign, and a new moves at his disposal. Meat is now the sole unlockable secret character outside of Taven, Daegon, and Blaze (who play major roles in the story mode). Blaze had a massive redesign, and is the final boss of the game.
Mortal Kombat (2011)
Reptile, Smoke, Jade, Noob Saibot, Quan Chi, Cyber Sub-Zero - In a very nice homage to the original games, once again Reptile, Smoke, Jade, and Noob are secret fights. Quan Chi, and Cyber Sub-Zero (who instead of Smoke, fell victim to their clan's betrayal) are unlockable through story mode.
My favorite MK character is Noob (the OG Sub). Ed Boon is also a big fan of his, so I'm hoping he ends up in MKX. Even if he isn't playable.