Guinness is certainly the most popular drink on St. Patrick's Day, but McDonald's Shamrock Shake probably comes in at a close second. It's only available for a limited time every year, which inspired Sam Jordan to drink a gallon of the minty concoction.
Or at least try to.
Filling an empty one-liter milk jug required six of the shakes, which amounts to just over 5,000 calories, or more than twice Sam's recommended daily intake. He started out drinking it with a straw, but it soon became obvious that chugging was the only way to go. Sadly, the sheer volume of Shamrock deliciousness got the best of him about halfway through, but since he's alive to tell the tale, more here.