Raikov appears in Metal Gear Solid: Portable Ops as an unlockable character, found by placing spies in the Western Wilderness before rescuing Naked Snake. Raikov had lost his position due to his abusive ways against soldiers (a reference to MGS3, where the player could attack Soviet soldiers without reprise when disguised as Raikov, as he was "just that kind of guy" from EVA's observations), and was imprisoned, to be released by Naked Snake and his team.
A spy for the PLA who assisted Snake in Snake Eater. Eva joins Snake's squad after completing an optional mission.
Teliko is a hidden character in Metal Gear Solid: Portable Ops who joins Naked Snake's team. The player can unlock her by having a Metal Gear Acid save file on their memory stick after completing the game, restarting a new game or saving the game at the first opportunity. Her appearance in the game is an easter egg and has no bearing in the story.
Venus is an unlockable character in Metal Gear Solid: Portable Ops Plus.
