Preheat oven to 120C. Grease a baking tray and line with baking paper.
Beat the egg whites in an electric mixer on low-medium speed until foamy. Add the cream of tartar and continue to beat the whites until they hold soft peaks. Add the sugar a little at a time and continue to beat until the meringue holds stiff peaks. Fold through vanilla essence.
Spoon meringue into a piping bag fitted with a 2cm fluted tube and pipe in a swirling motion to form a ghost, ensuring each meringue is 2cm apart. Bake for about 45-60 minutes. Cool in the oven with the oven door slightly ajar.
Using the back of a teaspoon, dip into melted chocolate and carefully dab on three small dots to make the eyes and mouth of the ghost.