🍔🎃 FREE Single ShackBurger at Shake Shack! 👻 From October 19 to 31, use promo code SCARYGOOD (all caps) and get a free Single ShackBurger when you spend $10 or more. That's a scary good way to treat yourself this Halloween! 🦇 📲 How to redeem: Enter the code at the in-store kiosk, in the Shake Shack app, or at shakeshack.com. It doesn't work at the drive-thru or on delivery apps. Limit one free burger per order, at participating locations. 📍 19300 Katy Fwy, Houston,