In a cocktail shaker, combine the coconut rum with the pineapple mango juice over ice.
Shake vigorously until chilled.
Prepare a glass by pouring the pomegranate liquor in first, then strain the shaken rum mixture over top.
Serve with a garnish of fresh sliced pineapple.
(If you aren't into showman ship, just toss it all into the cocktail glass and grab a whirly straw.)