Sometimes a cease-and-desist letter sent to the creators of a fan project can be a good thing. Sure, you can't use the licensed property that inspired you anymore, but creative minds can still produce something exciting. You might, oh, I don't know, be in the middle of making a My Little Pony fighting game when Hasbro gives you the wag of its legal finger, and you just might take that as the chance to make a game like this:
What you see is the result of My Little Pony: Friendship is Magic fans, calling themselves Mane6, who wanted to create a fighting game based on the beloved characters. Unfortunately, Hasbro's lawyers weren't prepared to love and tolerate the group's efforts, and a cease-and-desist order was sent to Mane6.
By that point however, the project had gained itself a dedicated following. When news of the C&D spread, the group - thanks to their own prominence and fan grassroots campaigns - earned the support of Skullgirls developer Lab Zero Games and Friendship is Magic's original creative director, Lauren Faust. That's Lab Zero's engine running Them's Fightin' Herds and those are Faust's designs you see in Arizona the Cow and Velvet the Reindeer.
This makes Them's Fightin' Herds both the closest fans will likely ever see of such a thing and a buttery-smooth fighter. It's still an independently produced effort, though, so the group has released a trailer showing a sneak peek at gameplay while simultaneously announcing a crowdfund campaign start date of September 21.
As for my thoughts, well, I'll let Rainbow Dash sum up my feelings: So! Awesome!