Pyros an extremely delusional arsonist who works at Mann Co. which is located in Teufort. Pyro sees everything in the world as rainbows, sunshine and lollipops because of the mask.  Any time they burn enemies with their flame thrower the mask causes them to see it as them spewing bubbles and rainbows at the other mercs.

Currently as pyro never revealed their true identity only one can imagine and shudders to do so.
This certain Pyro works for Builders United League which is also known as BLU 