Pinkie Pie - Stout Halfling, College of Glamour Bard, and Entertainer
 
Stout Halfling was obvious – Pinkie is a very homey person with a strong appetite for feasting and partying and quaffing, and that just shouted halfling to me.  
Bard was also a quick conclusion to reach, although I briefly considered trickery cleric and some manner of warlock in service to an endless party. But no. Pinkie is Pinkie, and she Pinkies entirely of her own volition. Glamour Bards are the most fey and wild subclass I could find, so I just went with that.  
Entertainer is just… there was no alternative, frankly.