The Thirst Zapper is the first unique weapon you’ll come across in Fallout 4’s latest expansion, Nuka-World. This is basically a water-gun that was designed to look like a laser blaster. It does no damage at all, and will only serve as an annoyance to anyone it’s fired at. It’s only use is against the very first boss you fight after reaching Nuka-World and clearing out the Gauntlet.
To find this weapon, play through the gauntlet until you reach the locker room before the boss fight against the electrified, armored raider. Search each locker and one of them will house this nifty little squirter. When you talk to Gage on the intercom, he’ll inform you that the Thirst Zapper is actually capable of shutting down the boss’s electrical field temporarily. If only it was able to shut down more enemies down the line.