http://www.overpwn.com/news/89-never-before-seen-datamined-hero-sprays-potential
We've got a treat for you tonight! We've datamined a load of Hero Sprays which are potentially going to be available in a future unlock system. Check them all out below!
Sprays are usable by heroes to tag the map with a picture. We aren't currently sure how you'll get to select which spray you get to use.
tbh most of these actually look pretty cool, although I hope there is a way to have a custom spray (I know it is probably not happening but a man can dream)