Justin Theroux plays Ann's friend, Justin Anderson, a very cultured former paramour of Leslie's.
Andy Samberg plays Carl, the head of security at a local park. He shouts a lot.
John Larroquette plays Frank Beckerson, a former flame of Leslie's mom. Hello Night Court.
Pamela Reed plays Leslie's mom, the no-nonsense Marlene Griggs-Knope.
Nick Kroll plays The Douche, an obnoxious deejay who goes on a date with Ann.
Detlef Schrempf plays, well, Detlef Schrempf. And basketball. And he's awesome.
Jay Jackson plays Perd Hapley, the host of the legendary show, Ya Heard? With Perd.
Mo Collins plays Joan Callamezzo, the brilliant and hilarious hostess of Pawnee Today.
And these guys - Racoons everywhere.