5. There's a secret menu drink called The Whataburger Hulk
It's created by filling your cup with ice, then filling between an eighth and a quarter of the cup with blue Powerade and topping the rest off with Vault soda. There are other variations that include The Insatiable Hulk, in which you swap Powerade with Orange Fanta. The Inconceivable Hulk consists of one quarter Vault, one quarter Fanta Orange, one quarter Powerade, one eighth Dr. Pepper, and one eighth root beer -- it’s supposed to taste like Bottle Caps candy. It may also taste like diabetes.