He has appeared in a number of television shows and movies, often portraying somewhat “ballistic” characters, especially on television shows. On the Nickelodeon television series iCarly, Rowley (as the character Lewbert) plays a mean and nasty doorman for Carly’s apartment building. On Carly and Sam’s web show, they have a segment called “Messin’ With Lewbert” where the two girls play pranks on Lewbert downstairs in the lobby of the building. On the show, Lewbert is recognized for having excessive anger outbursts, (i.e. when people walk all over the floor he just mopped).
Rowley has also appeared on The Amanda Show, most notably the sketch called “Blockblister” (a parody of the video retail chain Blockbuster), where he plays a customer who is angry because he did not get the movie he wanted (he paid for the video by tearing off his arm and giving it to them, replying “Keep the change!”). Again, he expresses his anger with loud outbursts in the scene. He is known as Ming on the podcast Comedy Bang! Bang!
Rowley is a member of the improvisational and sketch comedy group called “The Groundlings” based in Los Angeles, California. He also voices Bunsen on the Nickelodeon animated series Bunsen Is a Beast, for which he gained an Annie Award nomination.