Although the idiom "birdbrain" refers to a stupid person, Bird Brain is a genius (ironically) and is one of the more competent villains that T.U.F.F. go up against.
Bird Brain is voiced by Rob Paulsen, who is famous for voicing Yakko and Pinky from Animaniacs and Pinky and the Brain, not to mention The Shy And Coward Wimp Stanley Ipkiss, Grey Fox from the Metal Gear video game series, and The Wackiest, Lunatic, Party Animal, Superhero Alter Ego The Mask In The Mask: The Animated Series, and also voices for characters from other Nicktoon shows like The Fairly OddParents, Danny Phantom, Back at the Barnyard, Tak and the Power of Juju, The Penguins of Madagascar, and others.
Bird Brain could be a parody of The Penguin from Batman, since he shares a monocle, a tuxedo, and the lack of flying like him. Peg Puppy also mistakes Bird Brain for a "crazy penguin" in his debut episode. It's also possible that he's a parody of the Hulk's archenemy, The Leader, due to the oversized brain and massive intellect.
Bird Brain's voice may also be a parody of Ted Baxter from The Mary Tyler Moore Show played by Ted Knight.
He is a bird, except he has teeth.
It is unknown why Bird Brain is considered a flightless bird seeing how his species of bird, which is a booby, can fly in real life. It's possible that he was born with a defect that keeps him from flying.
In Bird Brain's first appearance in Snapnapped, the monocle is on his left eye. In all other episodes, the monocle is on right eye.
It’s revealed in Booby Trap that he is the second or only blue bottomed booby in existence.