His real name is Arnold, but one day someone called him Armpit and it stuck. In terms of his bartending business, he is willing to pay money for scorpion tails in order to establish production of radscorpion liqueur.
During the game, he will be rescued by the player character when the local raiders in Carbon show up to cause problems in his bar. When the player character returns to Carbon after a fight with the mayor, Richard, they see Carbon in flames, attacked by the raiders who were enraged at the townsfolk for the deaths of their men in the bar. Jane, the raider matron, confronts Armpit, but he is unable to talk himself out of trouble, so she orders one of her raiders, armed with a flamethrower, to kill him. Being burned, but still living, Armpit had an opportunity to say his final goodbye to the Initiate and even gave them the recipe for the radscorpion liquor. He died, trying to tell a joke to the Initiate to keep them closer to himself, being afraid to die alone.