I remember an ending to one of KP's video on John de Lancie (http://www.youtube.com/watch?v=uryn-IS1lpg&t=4m16s) and thought using Derpy for the Porky Pig parody ending, but decided to work with Pinkie Pie cause, she kinda fits.
Pinkie Pie (c) Hasbro, Inc.
Art by MofetaFanBoy