Overwatch’s Roadhog has a lot of accessories and armor pieces that comprise his costume, but the gun he wears across his back is the most iconic. Redditor SledgehammerCosplay made a commission piece for a friend and spent just five to seven hours making the prop. They pulled reference material from Blizzard and printed out a to-scale version. Then they used EVA foam layers to construct the base and glued them together with contact cement. You can see a couple in progress photos below and note that he primed it with white paint first so the different hues of brown would stand out.
Read more at Imgur.