Worn at: Genericon 2013, AnimeNext 2013, NYCC 2013, 4/13 NYCstuck meetup
The gas mask took me a month and a half to make. Besides that, I patiently cobbled the pieces of this cosplay together over the course of six months.
Here's a tutorial on how I made the gas mask: http://outstretched.dreamwidth.org/73903.html