the pyro can do many things such as climb your screen, surf the web for fresh memes, clone himself, and much more. You can have 1 pyro or many, its your choice. I've created a small Pyro desktop buddy that will screw with your windows and be a general nuisance. I don't know what possessed me to make this but i did it anyways.
UPDATE: NOW WORKS FOR WINDOWS!! THANK YOU JORG3234 !!!