One can obtain this outfit by killing Butch in Rivet City.
If the player character has sabotaged Vault 101, they can loot the Tunnel Snake outfit from Freddie Gomez's body in a random encounter.
The Lone Wanderer can reverse pickpocket better armor on him without having to sabotage the vault, by taking better armor with them inside, such as raider armor.
Three more can be obtained in Vault 106. One will need a Stealth Boy and three suits of average condition armor. When reaching the Survivor, trigger the hallucination and activate the Stealth Boy. Pickpocket the armors onto the hallucinations of Butch, Wally, and Paul, and sneak back to the living quarters. Come back and they should be wearing what was given to them and their outfits can be pickpocketed.
These clothes appear in the game files for Fallout: New Vegas, but are only obtainable through console commands.
Bandana ·Button's wig ·Chinese commando hat (Hat of the People) ·Confederate hat ·Eulogy Jones' hat ·Head wrap (Three Dog's head wrap) ·Hockey mask (Ledoux's hockey mask) ·Lincoln's hat ·Oasis druid hood (Poplar's hood) ·Party hat ·Pint-Sized Slasher mask ·Police hat ·Pre-War baseball cap (kid's baseball cap, Takoma Park little leaguer cap) ·Pre-War bonnet ·Pre-War hat (shady hat) ·Sheriff's hat (Paulson's hat) ·Stormchaser hat ·Wig ·Winterized Chinese commando hat