You can. If you do that, you'd likely be sued by the owner of the real Iron Man trademark (well, they'd send C&D first and if you don't stop they'll sue). But i

You can. If you do that, you'd likely be sued by the owner of the real Iron Man trademark (well, they'd send C&D first and if you don't stop they'll sue). But it's not likely you'd suffer any prosecution from the regulators. Of course, people legitimately dealing with Iron Man IP would otherwise ignore you, since they know who the real owner is. You may cause trouble to some people that are fair-using some Iron Man IP, but no more than Marvel already causing them anyway (probably much less).