My Little Pony Rainbow Dash Headband with Ears. Dress up like the intensely loyal member of the Ponyville weather patrol from My Little Pony: Friendship is Magic! The My Little Pony Friendship is Magic Rainbow Dash Headband with Ears makes a great roleplay, cosplay, or Halloween costume piece. It is one-size-fits-most because it stretches to fit the wearer s head, and the adjustable band is covered for comfort.