Driven slightly demented by lack of sustenance, and fearful of his life after a narrow escape from a Super Mutant bonfire, Carlos has set up a begging station at the entrance to Rivet City. Through the haze of dehydration, he remains hopeful that a water caravan or kindly stranger will cross his path.[1]
Water Beggars: He is asking for purified water. Giving him one will instantly grant the Lone Wanderer 50 points of karma and can be repeated infinitely.
As a non-essential non-player character, Carlos can die, usually killed by wandering hostile characters or falling off of the Rivet City bridge. Planting better armor and a gun on him can increase his chances of survival.
PlayStation 3 If you save your game while standing next to him, kill him, and load a previous save, he may appear to be lying the way you killed him, but without any limbs missing. If you talk to him he will return to his normal sitting position.
Carlos will die if you give him aqua pura whether or not you infected the water with FEV in Take it Back!.
References
↑Fallout 3 Official Game Guide Game of the Year Edition p.65: "Carlos Driven slightly demented by lack of sustenance, and fearful of his life after a narrow escape from a Super Mutant bonfire, Carlos has set up a begging station at the entrance to Rivet City. Through the haze of dehydration, he remains hopeful that a water caravan or kindly stranger will cross his path." (Fallout 3 Official Game Guide Game of the Year Edition Wasteland Census)