Porno Premises in MLP! Likely the cheesiest ones!
Feel free to use familiar characters, your own, make new ones, whatever works. Also feel free to go Equestria Girls, regular pones/zebras/griffons/whatever, et cetera. The world is your porny oyster.
Heck it doesn’t even have to be SFW if you just wanna do some goofy jokes 😀
You’ve got 45 minutes to create followed by 15 minutes to submit! Have fun~