This is the just released Starbucks Zombie Frappuchino, a limited time beverage released for Halloween (and only available from October 26th to 31st). The green caramel apple flavored beverage is supposed to resemble zombie skin with a dollop of dark mocha blood and pink whipped cream brains on top, although the brains look more like the turd of a dog who ate crayons to me. Still, if it's anything like their Unicorn Frappucino from earlier this year, everyone will still go buy one, post the absolutely perfect picture of it on Instagram, then complain how it tasted like complete ass, like you could honestly expect anything different.
Keep going for a review of the drink by Business Insider (SPOILER: they didn't like it).
Thanks to Kate, n0nentity and Stephanie B, who agree if your'e going to spend six dollars on a novelty drink, it better be served with alcohol in a collectible keepsake cup.