Preheat the oven to 225° F (107°C) Line a baking sheet with parchment paper. Set aside.
Separate the room temperature egg whites.
In a mixing bowl, beat the egg whites with the cream of tartar using an electric mixer on slow speed at first, gradually increasing the speed until the egg whites have formed foamy soap bubbles about 5 minutes.
Turn the mixer up to full speed and start adding the sugar, one spoonful at a time. Keep whisking until the meringue has a stiff, glossy appearance. It’s ready once it holds its shape, about 2-5 minutes after adding the last sugar.
Spoon the meringue into a piping bags with a Wilton 2A tip, shaking it down into the bag, removing any large air bubbles carefully. It should fill 2 bags.
Holding the piping bag with both hands, position the bag about 1/2 inch from the parchment paper and squeeze the bag to start forming the body of the ghost. Keep the bag steady while squeezing.
Once you’ve squeezed out the body, lift the bag just slightly, then push down and squeeze out the top part of the body, which is smaller than the base. Lift the piping bag straight up to leave a peak on the top of your ghosts' heads. It will take practice.
Keep forming ghosts, as quickly as you can, until the mixture is gone. Bake for 50-60 minutes until the ghosts are crisp on the outside.
Turn oven off. Allow the meringues to cool in the oven for at least an hour before you remove them.
Use the edible pen to draw faces on the ghosts.