I’ve just heard about the thing where MLP Flash animation assets from DHX were leaked about a year ago and some people have gone and used them illegitimately for fan-animations.
I’m not here to say what’s wrong and what’s right about that (it’s wrong), but a proper definition of “fan-” as a suffix generally refers to original content made by fans based on an existing work, like MLPFIM (edited for clarity). And ripping these protected assets to conform to your animated whim brings it to the grey area where sprite comics are. The models and sprites are already there, but you didn’t necessarily create them. And also that these leaked assets are protected assets and using them out of the scope of where they are supposed to be is, by definition, illegal.
I, for one, started doing fanart for the love of the medium. Vector graphics turn me on with their sharp lines without degradation from scaling. My intended goal when I started vectoring ponies was show-accuracy.
I knew the inner-workings of Flash animation and so I had it right from the start when I made a base-model of a pony from scratch (namely Twilight, my first vector) I knew I could reuse, and did so through analysis of the show’s characters and common practices.
It took a bit of effort until I built what I wanted. It didn’t turn out quite like the show’s but it was months after then that I realised that through all the tweaking and changes, I created something unique. Something that was almost show-accurate, yet a style of my own.
There are many other fan-artists and animators who probably followed a similar path. Taking the time to create their own batch of assets for their fan-work. It’s hard work, yes, but it’s so much more rewarding when you can sit back after you’re done and say “I made that”.
We all start from somewhere and it’s always easy to take something that exists and modify that as yours, but work on it and soon you can build something that’s custom and unique to your style.
tl;dr: Don’t use Hasbro’s assets or they’ll beat all our butts because their lawyers can’t tell the difference.