Piano man Cosmo Brown is Don Lockwood's best bud. Friends since childhood, they rose through the Hollywood ranks together via vaudeville.
Cosmo is an athletic, rubber-faced, hilarious ham. For evidence, look no further than the "Make 'Em Laugh" dance number, "in which he manhandles himself like a cartoon character," according to Roger Ebert. He pulls silly faces; takes a wooden plank to the back and front of his head; smashes into a brick wall; romances a headless dummy; and runs up, and flips off of, not one, but two walls before collapsing. He's like all of the Looney Tunes roster rolled into one trim little dude.
The Baloney Police
But don't be fooled: Cosmo's more than just comic relief. He's a shrewd and frequently snarky observer of Hollywood's rampant absurdity. For starters, he keeps Don's movie star ego in check. When Don starts down a self-pity spiral after The Dueling Cavalier's disastrous preview, Cosmo snaps him out it. "Well, at least you're taking it lying down," he jokes. When R.F. and Dexter express their misguided confidence that talking pictures will never ever catch on, Cosmo jibes, "That's what they said about the horseless carriage," a.k.a. THE CAR.
He also never misses a chance to put Lina in her place. When Rod from the publicity department tells Lina they can't let her make speeches in public because the studio has to protect its stars from looking stupid at any cost, Cosmo's quick to chime in. "No one's got that much money," he says.
Ultimately, Cosmo is much more than a court jester; he's Monumental Pictures' wisecracking conscience. He's always quick with a quip, and he has many of the film's best lines.