The Cashier is a character in Thing Thing Arena 2. He wields a Mini Vulcan and shoots at anyone who fires at him enough times. If killed, he drops his Mini Vulcan and it will act like the rest of the guns in the training room, and the Mini Vulcan is also unlocked for use in all gameplay modes. The best way to kill him is to take advantage of his Mini Vulcan's size. Since it is so large, standing directly in front of him will make him unable to damage you (you could say his blind spot). Then, use a small firearm (HF Laser Pistol) to take him out with no chance of retaliation.