Santa's Little Helper

Muddle a sprig of fresh mint in a shaker. Add cubes, rum, and watermelon juice to the shaker. Shake until cubes have dissolved. Pour into a collins or rocks glass and squeeze in a wedge’s worth of lime juice. If desired, top with a little sparkling water for some fizz. Garnish with a sprig of mint and a lime wedge. Toss a few cranberries in if you’re feeling extra festive (Santa certainly would).