Just as refreshing as it sounds.
In a blender, combine the fresh watermelon chunks and mint leaves. Blend until smooth.
Strain the watermelon-mint mixture through a fine-mesh strainer into a cocktail shaker to remove any pulp.
Add vodka, lime juice, and simple syrup to the shaker.
Fill the shaker with ice and shake vigorously until well-chilled.
Strain the cocktail into a tall glass filled with ice.
Garnish with a small watermelon slice and a sprig of fresh mint.