- Cast the Expert: Black belt and stuntman Daniel Bernhardt (his best known acting roles being an Agent in The Matrix Reloaded and the hero of Mystery Science Theater 3000 subject Future War) plays a would-be target who along with his even more badass daughter gives Barry the fight of his life.
- The Danza: Chris Lucado, played by Chris Marquette.
- Dyeing for Your Art: Bill Hader exercised extensively in order to develop the body of an ex-military hitman-although, as he admitted in this interview with Conan O'Brien, no one noticed the difference.
- Reality Subtext: Bill Hader's much-lauded run on Saturday Night Live was a time of deep anxiety for him, with Hader getting frequent panic attacks and migraines from the stress. He used the idea of being gifted with a talent that causes you endless grief to create Barry's motivation.
- What Could Have Been
- NoHo Hank was intended to die in the first episode, but Anthony Carrigan's performance ended up endearing the character to the staff, resulting in him not only living past the episode, but being the Sole Survivor of the Chechen mob by the end of the season.
- Ronny from the episode "ronny/lily" was written as a short, fat, unassuming-looking guy in order to make the reveal of his mastery of taekwando more of a gag. In a case of Real Life Writes the Plot, all of the taekwando stuntmen that auditioned for the part were tall and in peak shape, forcing the joke to be dropped. In fact, Daniel Bernhardt, the actor eventually cast as Ronny, was chosen specifically because the show's female staff found him to be incredibly handsome.
- Writing by the Seat of Your Pants: Bill Hader has admitted that he and the writing staff mostly play it by ear when writing each episode, and don't structure the seasons very concretely in advance.
Trivia / Barry