How about, instead of the movie "The Thing" (the original from 1982) to The Changeling as a spoof, where they find out which one is a changeling and who's a real pony some of the mane characters that takes place in Antarctica, instead, taking place somewhere far away from Equestria. And there's this changeling thing going around taking over the pony race doesn't matter if you're an earth pony, unicorn, pegasi or an alicorn or any of the crystal variants of those. They will take over the whole Equestria nation, and become one of you.