In Tomb Raider's multiplayer the island's indigenous scavengers are the enemies that attack the crew of the shipwrecked Endurance. This will be set in the most dangerous areas of the island as players will use the hunting and trap setting skills they learned in single players to take out each enemy.
To be honest, this MP will be dead in less than 6 months. FYI, Uncharted 2 MP still is active and UC3 has a very strong community (as well as worldwide competitive tournaments once in a while).
TR multiplayer is something that I can't say anything other than to bash it lets leave it at that.