Watermelon and Mint Margarita

Merry Christmas ya Filthy Animal!
To get into the festive spirit try this Watermelon and Mint Margarita (aka the Filthy Animal).
1. Salt the rim of a glass with black salt
2. Muddle 3 chunks of watermelon and 3 mint leaves in a shaker
4. Shake vigorously
5. Strain into glass and top with fresh ice