Mallet McBride is not a nice man. In fact, he's a downright asshole. If it weren't for the fact that Mallet was in prison for carrying Limit 115, he would be either in someone else's prison, or dead from a gunshot wound to the head. However, now that he escaped Tibbets Prison, he has chosen Hoover Dam as the place to sow his wild oats.
Mallet is a pretty big guy and a very skilled unarmed fighter. He's so good, in fact, that legend has it he once laid out a super mutant with one punch, though that legend has never been tested on Beatrice. Mallet hangs out in Dusty's Desires and whittles the day away getting drunk and boozing it up. He takes the occasional caravan job with Crimson Caravan to earn enough money to continue his boozing and carousing, but he does not have any loyalty to them.
Should the Prisoner approach Mallet about taking him back to Tibbets, then they had better be ready for a fight. Mallet will not go quietly and will begin to punch the prisoner in the face until he is dead. A similar reaction will arise if the Prisoner approaches Ginger Flowers for the same reason, she will seek Mallet's protection and a fight ensues.