This story is a sequel to Rainbow Dash, Element of Magic
April Fool's Special!
It's National Pranking Day, a holiday to let everypony have fun by pulling harmless pranks on each other, and it's Fluttershy's favourite holiday (and Pinkamena's most hated holiday), so of course the pegasus of Laughter is thrilled to join in the fun, especially now that a Professional Prankster Pony (PPP) is willing to help make everything double funtacular!
Dr Prankie is going to change how ponies celebrate National Pranking Day forever!