Whiskey Fiends are a particularly bad bunch of Fiends who sell whiskey and cigarettes to children. They hide out in the destroyed houses near the Sunset Sarsparilla HQ. When Al is in need of supplies, particularly whiskey, he will usually go to the whiskey fiends and take it from them.
While on a mission for a citizen of Skunkwater Gulch in which he has to find bottles of whiskey, Steve, in his infinite
knowledge, lets Al know of the location of the Whiskey Fiends, who have crates full of it.
He travels to the Sunset Sarsparilla HQ and fights the Fiends to the death while stealing all of their whiskey, not only for the mission, but to stop the Fiends in their illegal sale of it to children. To say the least, both missions were a success. The Whiskey Fiends never truly recovered from Al's assault and as a result the many surviving members left the gang.
They've recently rebanded in the Sunset Sarsparilla HQ, during Fallout New Vegas Mods: Thomas Pinkerton Revengeance - 2, under the leadership of Suzie Q, a demonic child. There, they attempted to ambush Al by having Suzie pose as a hostage, only to be immediatly gunned down. They made occasional appearances after this.