In a large pitcher, combine watermelon juice, lime juice, agave and mezcal. Stir to combine. Pour into large ice cube molds, a plastic container or a gallon Ziplock bag.
When ready to serve, combine with ice in a Vitamix or blender. Pour into cups and garnish with wedges of watermelon.
Makes 4 drinks
*Cut seeded watermelon into chunks. Blend on high until smooth. Strain through a fine mesh sieve, discarding pulp. Chill until ready to use.