Unless it was another MGS character. I don't remember seeing one on the list though.
This guy is the MGS minion for raiden, not snake.
And until I have definitive proof, I am going to be stubborn and stick to the one minion per character rule. Here is the minion list again for comparison.
Original Six
Athena / Kratos / God of War
PJ Berri / Parappa / Parappa the Rapper
Worker / Fat Princess / Fat Princess
Dollface / Sweet Tooth / Twisted Metal
Helghast Soldier / Radac / Killzone
Murray / Sly Cooper / Sly Cooper
Official Announcements
Sully / Nathan Drake / Uncharted
Little Sister / Big Daddy / BioShock
Pierre / Toro / Doko Demo Issho
Kuma / Heihatchi / Tekken
Keira / Jak & Daxter / Jak & Daxter
Zeke / Good Cole / inFamous 2
Leaked Characters
Nix / Evil Cole / inFamous 2
Captain Qwark / Ratchet & Clank / Ratchet & Clank
Sackbot / Sackboy / LittleBigPlanet 2
Kai / Nariko / Heavenly Sword
Kiya / Sir Daniel / MediEvil
Monkey / Spike / Ape Escape
Kat / Dante / DmC Devil May Cry
Sam / Raiden / Metal Gear Solid Rising
Do you guys still think those two fit in that list, messing with the 1 minion each rule? I guess it's possible.