The Arbynator features thin-sliced roast beef, curly fries, cheddar sauce, Arby's sauce, and Horsey sauce on a toasted sesame seed bun. It's available in Classic, Double, and Half-Pound sizes.
The Arbynator will be available at participating locations nationwide through December 23, 2018 (although given that all the components are part of the regular menu, you can still custom order it once it's off the menu).
Photo via Arby's.