Place clear plastic cups on a clean flat surface. Keep your spoon, marker, and marshmallow fluff close so you can work smoothly.

Scoop a spoonful of marshmallow fluff. Because it is sticky, move slowly and press gently.

Smear the marshmallow fluff inside the cup, shaping it into a tall ghost form. Make three to four ghosts per cup for a cute effect. Smooth edges lightly so the shape stays neat.

Turn the cup so the fluff ghosts face you from the outside. Using a black marker, draw two eyes and a mouth on each marshmallow ghost. Allow the ink to dry briefly before continuing.

Slowly pour chocolate milk into the cup. Because you want the faces to stay visible, pour gently and avoid splashing. Fill the cup to your preferred level.

Serve immediately or chill briefly for a colder drink. Optionally, add a straw for serving.