How to Cosplay As the Pyro from Team Fortress 2

Choose a side: RED or BLU mercenaries. Once you have decided, get a bodysuit/jumpsuit of that color (blue might be harder to find).

Wear a black utility belt.

Wear black clip-on suspenders on the belt and over your shoulders.

Wear a pair of black combat boots.

Wear a black gas mask covering your entire face. A balaclava can be used to create the illusion of a gas mask that covers your entire head. A non-black gas mask like the PMG-2 can also be used, as they often appear as cosmetics for the Pyro.