Good luck, John Larroquette. Following last night's hilarious guest-starring stint by Will Arnett, you have some big, funny shoes to fill.

The former Night Court and Boston Legal star is coming aboard the NBC sitcom Thomas Beckerson, a former flame of Leslie's mother, Marlene.

"He's the one who got away," series creator Greg Daniels told TV Guide Magazine. "Leslie's trying to find that guy and bring him to her mom."

Co-creator Michael Schur expounded on the storyline, which will take place on the show's Valentine's Day-themed episode:

"Leslie and Justin Theroux's character go on a road trip to Illinois to grab this guy and bring him back," while Daniels added that Leslie will be "running a Valentine's Day dinner dance at the Senior Center."

Consider our funny bone properly intrigued.

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.