So, about those robot chickens. The scene being filmed takes place in a seedy Tijuana flophouse, and the situation is this: Alan [Galifianakis], Phil [Cooper], Stu [Ed Helms] and Chow [Ken Jeong] are being viciously attacked by a swarm of bloodthirsty cocks.
“Oh, fuck! Motherfucking roosters!” Chow screams on the monitor.
It’s chaos. Only moments before, Alan had unwittingly set free a horde of fowl after perching himself on a covered cage that just so happened to be housing a horde of savage cock-fighters. Now the birds are on the offensive, pecking and clawing any piece of man-flesh they can get their beaks on.
An (animatronic) rooster flies directly at Phil, fluttering its wings with a terrifying intensity. Phil flies backward onto the bed, and then over it, as the bird latches on. A second later, Chow leaps up onto the bed, pistol in hand.
“That’s my rooster, bitch!” he wails. And then -- BLAM! -- the sound of the pistol cuts like a knife through the bedlam. It’s pointed at Phil's cock. Or rather, the cock on top of Phil. You get the gist.
“What the fuck!” Phil screams.
“I’m trying to help!” Chow yells back.
And so on. 

An official image from The Hangover Part 3 featuring Ken Jeong

“There was one, that third take, I think, where there were four chickens descending on me,” says Ed Helms of shooting the scene. “And I watched playback and I definitely had a little Hitchcock recollection there.”
Helms speaks to us in his trailer during a break from filming. While he’s just as non-specific as Cooper (a clear directive from the film’s PR reps), he at least adds a little more color to his non-answers.
“[Stu] does marry this woman who is-- he clearly marries up,” says Helms – whose character tied the knot with Lauren [Jamie Chung] at the end of the second film – of where we find Stu in the threequel. “She's a beautiful, intelligent woman and, as a result, in ‘[Hangover] 3,’ we pick Stu up into that marriage and having clearly absorbed a little bit more responsibility for-- He's a little bit cooler of a guy. Do you know what I mean? He was more-- He was happier in the first two, I think, to just be a nerdy dentist. Now I think his wife has dressed him a little bit cooler, has…he has different glasses this time, they're a little bit cooler. And he wears these cool socks.”
Oh yeah, the socks. They’re very colorful, and also not really that cool, except perhaps for a person who’s trying very, very hard to be cool.
“The wife has sort of, hopefully, made him look cool at the beginning, but then, of course, good old Stu comes out,” he continues. “Huge, huge nerd.”
So, what else? Ah, here’s something.
“Todd's direction is informed by more Martin Scorsese than Mel Brooks,” say Helms, diverting from a question about the dark turns we might be able to expect from Stu in the threequel. “And so I feel like a lot of that stuff, a lot of it, is really coming to bear in this movie. And as I watched playback, as I watched little pieces that we've shot-- Sometimes we'll watch a scene from a few days ago just to make sure we're doing today's work right, and it's just like, ‘Holy shit, this looks incre—‘ It just looks like a fuckin' movie, you know? It doesn't feel like-- It's not like-- It's just not another comedy off the shelf. It feels like a real cinematic experience.”
“’The Hangover Part III’: A Real Cinematic Experience...With Cockfighting." Hey, I like it.
A former contributor to sites including MTV's The Backlot and Bloody-Disgusting, Chris Eggertsen worked in film development before indulging his love of pop culture writing full time. He specializes in horror, the intersection of social issues and entertainment and Howard Stern. He's on Twitter @HitFixChris.