We've already seen a guy who looks just like Mario of 'Super Mario Brothers' fame doing his shopping at Walmart. Now we might just have found another video game character. Just like Mario has Luigi as a sidekick, Sonic the Hedgehog has Tails. Sonic must be just out of frame in this shot, but we've definitely found Tails. He's just a little shy, and he's hiding up the back of this man's t-shirt.
All joking aside, we have no idea what's going on here. Everything else about the way this man is dressed and his demeanor is completely normal. The fox tail just seems to come from nowhere, and doesn't serve any purpose other than to confuse people who are looking at him. Maybe that's the whole point of it? It doesn't look very practical - we can't imagine it's much fun to sit down on.