 Howerton is most notably involved in "It’s Always Sunny in Philadelphia" (2005-) as one of the main cast, producer and director, he also has written numerous episodes.He planned to be executive producing on the comedy show "Boldly Going Nowhere" with his "It's Always Sunny in Philadelphia" co-creators, before the show was delayed.Howerton had a recurring voice role on "The Cleveland Show" as Ernie Krinklesac, as well as recurring roles on the Fox comedy series "The Mindy Project" and the FX dark comedy series "Fargo".