My Little Pony Classic Costume - X-Small Our My Little Pony Halloween costume includes a tunic with detachable tail, leggings, and headband. The Rainbow Dash costume style also includes detachable wings. Choose from Rainbow Dash (blue) or Pinkie Pie (pink) for your My Little Pony Halloween costume. Our My Little Pony Halloween costume comes in child sizes X-Small, Medium, Small. This My Little Pony Halloween costume is an officially licensed My Little Pony costume.