Jeff Daniels' agents were so certain that Dumb and Dumber was going to be the flop of the century that they staged an intervention in order to attempt to convince him not to co-star with Jim Carrey. Of course, Jeff didn't listen. And fans everywhere are thrilled that he didn't. The 1994 film, which was co-directed by Peter and Bobby Farrelly, went on to spawn a franchise that even had an animated show for a time.

The original movie's cringe-worthy comedy is easily what gets people revisiting it decades after its release. Among the most inappropriate gags involves a dead budgie that's sold to a sweetly naive blind boy in a wheelchair. While the cast and crew of Dumb and Dumber told MEL Magazine that it may be the movie's most 'cancel-worthy' joke, they're also aware it spawned countless memes, merchandising, and just made people laugh. Here's the hilarious origin of the uncomfortable gag...

6 The Real Origin Of The "Pretty Bird" Joke In Dumb And Dumber

According to the co-screenwriter of Dumb and Dumber, Bennett Yellin, the origin of both the film and its most inappropriate joke dates back to the 1980s and acclaimed director John Hughes.

"Back in the 1980s, Peter and Bobby [Farrelly] and I would get hired to rewrite other people’s scripts, and he had read something of ours and thought we were funny. He called us to his office and started telling us about this idea he’d had while at Warner Bros," Bennett told MEL Magazine. "These two guys had come to his mind — Harry and Lloyd — and he ended up writing like 50 pages about them. But there was no plot. It was just these two idiots running around a ski resort. When we met with Hughes, he gave us the 50 pages and told us, 'Come back and pitch me a movie.' We went away, came back and pitched the entire plot of Dumb and Dumber to him. He loved it, so he told us to go write it."

Related: The Reason Jeff Daniels Was Forced To Shoot Scenes Without Jim Carrey In 'Dumb And Dumber'

Bennett continued by saying, "Peter and Bobby’s family is from Rhode Island, but they also had a home in Hyannis, Massachusetts. For the summer of 1990, they stayed with their parents in Hyannis, and I stayed in a cottage nearby. They’d come over every day, and we’d work on the script. I was always the one at the typewriter because they were terrible typists, but we were really just one hive mind on that script, so everything that went down was truly all three of us. That’s where we came up with everything, including the “pretty bird” scene. Although, in 2019, Peter and I went to a Dumb and Dumber screening, and afterwards we did a Q&A. Peter said that when we were pitching the movie to John Hughes, I delivered the joke about the bird’s head falling off, and Hughes fell out of his chair. I had no memory of coming up with that, but Peter was sure of it."

5 What Is The Bird's Name In Dumb And Dumber?

Like any great joke, specificity mattered when crafting the "pretty bird" scene. And that specificity was in the form of a very cute and heartbreaking name... Petey.

Related: How Lauren Holly Really Felt About Making 'Dumb And Dumber'

In his interview with MEL Magazine, Bennett Yellin explained that he came up with the bird's name because he was a fan of Albert Brooks and the film Modern Romance where he had a bird of the same name.

4 Who Was The Blind Kid In Dumb And Dumber?

Brady Bluhm played the blind kid on Dumb and Dumber who gets duped when he's sold a dead bird he just thought was "quiet".

"I started acting at five years old, mostly episodic TV and guest-starring roles. I was 10 when I auditioned for Dumb and Dumber," Brady Bluhm said to MEL Magazine. "The first time was just me, a casting director and a camera, but the second was in front of 12 or 15 people. I started doing the lines, and everyone in the room just roared with laughter. I remember thinking, 'I don’t get why this is so funny, but I think they like me.'"

3 What Happened To The Bird In Dumb And Dumber?

Worry not animal lovers, there was no real bird in Dumb and Dumber. At least not in terms of the scene in question. However, actor Mike Starr, who played Joe Mentalino, the man who ended Petey's life, said that he made the scene so much more graphic than it was originally intended.

Related: 15 BTS Facts About Jim Carrey And The Cast Of Dumb And Dumber

"For the scene where I break the bird’s neck, I never dealt with a real bird — there was just a dummy," Mike explained. "In one take, I took the bird and threw it against the wall, but they wanted something 'smaller' just to show what a mean b*stard I was, so I broke its neck, just offscreen. That’s the take they went with."

2 Was The Bird In Dumb And Dumber Actually A Prop

Yes, the Petey in Dumb and Dumber was absolutely a prop. Brady Bluhm claims that it was just a wire with features with a head taped on. Bennett Yellin added, "Sydney Bartholomew would have made that prop. Unfortunately, he’s no longer alive. He was a great production designer, and he did just about every movie Peter and Bobby did before he passed away."

1 The Most Famous Dumb And Dumber Line Was Improvised

In their interview with MEL Magazine, the cast and crew admitted that the Petey the dead bird gag is one of the things in Dumb and Dumber that hasn't aged well. Not just because of the cruelty to animals gag but also the joke on the young blind boy. Still, they know it continues to get huge laughs. And so much of that has to do with Brady Bluhm's improvised line...

"I improvised that line! 'Pretty bird' was in the script, but I improvised 'Polly want a cracker?' and they left it in!"