The first line of a complaint a Minnesota burger joint filed against McDonald’s reads, “This is a case of David versus Goliath.”

In the complaint, the Lion’s Tap of Eden Prarie, Minn., accuses McDonald’s of violating trademark laws by using the phrase “Who’s Your Patty?” to market the new McDonald’s Angus beef burger. Owners of Lion’s Tap claim they registered the “Who’s Your Patty?” mark in Minnesota four years ago and filed a trademark application with the U.S. Patent and Trademark Office this year.