10 cups diced seeded watermelon
1/2 cup water
1/3 cup agave nectar
1 1/2 cups tequila (such as Patron®)
1 cup frozen blueberries
1 sprig mint leaves, for garnish
Blend the watermelon in a blender until smooth; pour into a large pitcher.
Stir the water and agave nectar together in a small bowl; add to the watermelon. Stir the tequila into the watermelon mixture. Add the blueberries and garnish with the mint to serve.