Martian Costume Mask

The costume only exists inside Martian Madness, and that invasion will not start until Golem is dead and a scouting probe has escaped to report your position. Once it is running, four of the ground troops carry the outfit: Gray Grunts, Ray Gunners, Scutlix Gunners and Brain Scramblers. Drones, turrets and the saucer never drop any of it, so a run built around killing the saucer as fast as possible ends the event with nothing to show.

All three pieces are cosmetic and the social slots are the point of them. The mask covers the whole head, which puts this among the few outfits that erase the face entirely rather than sitting on top of it. Because the event has to be running to farm anything, pick up spares while you are in there instead of counting on another invasion showing up soon.