This includes:
Snake- The main character.
Liquid- Snake's evil brother.
Meryl- Woman snake falls for in MGS, found in a cell at the enemy base.
Wolf- Sniper who falls at the hands of Snake.
Ocelot- Handgun fanatic with excellent aim.
Psycho Mantis- Strange mind reader who can float and use telekinesis.
Metal Gear- The giant robot at the end of Metal Gear Solid, now a tiny, grey bot!
Armory Guard- The weakest of all the guards.
Base Guard- The basic guards, who are everywhere in the game.
Snow Guard- The guards in the sub-zero areas.
Enjoy. This works best with Landwarrior mod. (Link in sig) Characters look similar to actual MGS counterparts with LW. There you go, the guards are in.