Hasbro seems to be turning a blind eye to copyright infringement, but they HAVE cease-and-desisted fan content creators. : /
If someone reports your content to Hasbro, legally they are obligated to pursue you and seek recourse, which could be anything from just warning you to get rid of all infringing content, to paying them licensing dues/profits from any sales you might make off their content, to suing you for losses or damaging their brand.
In order to defend a copyright in court, the owners of the intellectual property have to pursue all reports of infringement fully. If they let one artist get away with it, then if it went to court a judge may be less likely to rule in their favour. So if its reported, you can bet Hasbro will act.
The one way around copyright infringement is if its considered parody. But then, parody is hard to define and measure and that's why good lawyers get paid a lot of money.
Don't get me wrong, I love seeing people make profit from their hard work. If what you do is good and people love it, it's awesome to get paid for it! But it's risky when it comes to the intellectual property of others.