Charon
In the Underworld, at the Museum of History, you can obtain a Ghoul follower named Charon. Go upstairs and to the left to the bar and talk to the Ghoul with the suit. If you choose the right dialogue you will be given the option to buy Charon for 2000 caps, or as i did, you can silently kill the waitress to earn him. I just shot her with my silenced 10mm while she was sleeping. He is a terrific friend to have, he is a crack shot with his shotgun. I haven't been able to give him another gun but i have given him very good armor. very nice!