Gas Masks (File:Gas Masks.png) were a limited time currency during the Act Two of the Terwilligers 2015 Event. They were earned different ways. * By tapping on Bob Clones that appeared on the streets of Player's Springfield. * By tapping on Bob Clones that appeared on their Neighbors' Springfields. * By tapping on Mutant Vegetables that appeared on their Neighbors' Springfields. * From April 28 to May 6, 2015, before the update. * Occasionally by catching Mutant Seed that appeared on the player's town. * By completing each act's questlines. * By completing Cecil's Daily Tasks * By completing Random Character Group Tasks triggered in the game, after completion of each act's questlines. * By collecting income from the Monsarno Research Campus.