Whenever someone says something that could be interpreted as being a dirty joke, Yakko blows a kiss to the audience, and says, "Goodnight, everybody."
Executive producer Steven Spielberg came up with the idea to have an original musical score in every episode.
During the theme song, the characters proudly announce that "We have pay or play contracts". This is a Hollywood term meaning the performer is paid whether or not he or she plays, this was a big deal in the days of contract studio players.
The Goodfeathers, a parody of the Warner Brothers film Goodfellas (1990) were made to reflect the personalities of the film's main stars. Bobby, the blue pigeon, is meant to be Robert De Niro, Pesto, the purple pigeon, is meant to be Joe Pesci, and Squit, the gray pigeon, is meant to be Ray Liotta. Also, the Godpigeon is a take on Marlon Brando from The Godfather (1972).
The show, during its initial run, was more popular with teenagers and adults than children. This became a problem, as The WB always placed it inside of their "Kids WB" programming block, which eventually caused the series to be cancelled, as sponsors of the block felt uneasy about footing the bill for an audience to whom they couldn't sell products.