It's Always Sunny In Philadelphia: 10 Cameos You (Probably) Missed
9. Retta
Retta has a very brief cameo in Season 4, Episode 12, “The Gang Gets Extreme: Home Makeover Edition.” She plays the clerk at a hardware store where Charlie and Dennis go shopping after they have kidnapped the Juarez family and are forcefully renovating their house. Retta doesn't say much, but her facial expressions as she listens to Charlie explain his taco bed plan to Dennis are brilliant.
Most famous for her role as Donna in Parks and Recreation, Retta also stars in Good Girls and A Girlfriend's Guide to Divorce. She can also be seen in Good Boys.