Replying...
Intro. She was a party and crazy pony at the same time, she liked sweets and cakes, as time went by she had gained so much weight that now she is a fat and big pony, when she meets you she wants you to have one last party with her since she thinks about losing weight but when she ate a cake with one of her friends she stopped thinking about losing weight and started gaining weight for you and that is why she has more parties to improve her fatness

Pinkie pie

@Adelmo Campos