Z's Fork Horners will give every rider $2 off any of their amazing burgers, sandwiches or baskets plus $3 calls and $4 Moscow Mules. If you have never had a Moscow Mule, they are spectacular! an awesome summer refreshing drink served in a copper mug. Anyone who tackles the 20 Inch Spread burger gets a free T-shirt and a free Moscow Mule. This is stage 2 on a quest to join the Order of Bill Underdown.