Start by washing all your fruit thoroughly under cool water. Hull the strawberries by slicing off the green tops, then cube your melon into bite-sized pieces. Leave the grapes whole since they thread onto the skewer easily as they are.
Dot a small amount of white icing onto the marshmallow where you want the eyes to sit, then press the candy eyes gently into place. Once the icing has set slightly, use your black food marker to draw a small mouth or spooky expression.
Give the marshmallow faces a few minutes to dry completely before handling them further. This step matters because wet ink or icing can smear onto your fingers or onto the fruit once you start threading everything onto the skewer.
Thread a marshmallow ghost onto your skewer first, followed by a strawberry, a melon cube, and a grape. Keep repeating this pattern, pushing each piece close to the one before it so there are no awkward gaps along the stick.
Once all your skewers are assembled, pop them in the fridge for a few minutes if you have time, since these taste best served cold. Arrange them on a platter and they're ready for snacking right away.