Step 1

Preheat oven to 225 degrees F (110 degrees C). Line 2 baking sheets with silicone baking mats.

Step 2

Whisk eggs whites and lemon juice together in a bowl until thick, white, and foamy. Add sugar a spoonful at a time, whisking constantly, until meringue is shiny, thick, and holds its shape.

Step 3

Transfer meringue to a piping bag. Pipe 12 bone shapes onto a prepared baking sheet. Pipe 12 puffs to resemble ghosts onto the remaining baking sheet.

Step 4

Bake in the preheated oven until dried and firm, about 1 hour. Turn off the oven, close the door, and cool until completely dried, about 1 hour more.

Step 5

Dip the tip of a toothpick into melted chocolate and dot chocolate "eyes" on each of the ghosts.