Happy Studio World, it looks like every single language other than English has their own pony game. I say game instead of creator, primarily because this little pegasus here is pretty picky! She will react based on what colors/hair/wings you toss on to her; everything from angry and snarling shown above, to happy and jumping found below. It's actually pretty well animated for a Mcdonalds game.
Head on over to this page, pick something other than English when the balloons pop up (I went with Italian personally), register your character (Choose female if you want pony costumes for your avatar), and go through the confirmation email step, then click Pinkie Pie to play.
Thanks to Михаил for the screenshots and heads up about it! Who would have thought to dig into some random McDonalds game for pony?