To enter the Free 20-oz Coca Cola Zero Coupon Giveaway, you will have to have a Twitter account and Tweet @CokeZero using #seesit or #doesntseeit! Wondering what we are talking about? Well, you will have to guess if the groundhog will see its shadow 🙂 If you guess right, you will receive a coupon valid for a Free 20-oz Coca Cola Zero (there will be 7,500 winners in total)! Good luck and be sure to let us know if you win a Coke Zero.