"We can name it The Whamper, The Slamopper, The Whoppaslam... well, we can figure that out later. We're throwing a #BigBurgerBash this month at Denny's, and you're invited. Let's grab a booth and talk," Denny's said.
Burger King accepted Denny's offer and took it one step further, inviting other restaurants to join in on the plans for an Atlanta pop-up.
Burger King said the Peace Day Burger is planned to include ingredients from the Whopper and Slamburger, as well as ingredients from signature sandwiches created by chains Wayback Burgers, Krystal and Giraffas.
The fast food chain said McDonald's is still welcome to join the project.
"McDonald's, please take your time. We're totally at peace with that," Burger King said.