This is a sketch drawn by Artca9 in a dead drawthread on a site that took in many refugees from 4chan during its temporary shutdown (I don't know if the direct site address is on the spam list at the moment).
Unfortunately Artca9 stopped drawing due to depression. It's a shame because I liked his drawing style, even though the, um, gas theme in some of the pictures was definitely not to my liking. The requests he was going to do were definitely interesting, but alas.