Transcript for Secrets from the set of your favorite holiday films
You know, Thanksgiving is around the corner and one Thanksgiving leftover to put away who doesn't love to just settle down, settle in, get a blanket and watch a good old-fashioned classic holiday movie. Love it. That's what I'm going to be doing. We have our favorites and "20/20" is going behind the scenes of some of the best and Chris connellily has a preview. What do you want for Christmas, little boy? Reporter: The beloved 19 3 holiday classic "A Christmas story" but the character of ralphty parker played by Peter Billingsley more than three decades later a successful producer he is sitting down with stars of other holiday classics discovering behind the scenes secrets to such films as national lampoon's Christmas vacation. Christmas is a very high anxiety period for most people. There was nothing in the box, right? No. That's all you. Those little physical things, boarding here and that was a big one for me and it worked. I always saw it as a love story because basically I have like one line, Clark! Clark, stop it. Clark. Clark. Clark, what's wrong? Everyone else rolls his eyes at him but you never do. Because this woman loves him. Reporter: Then there's "Elf" which featured a cameo from Peter Billingsley as his pal director Jon Favreau explains. I wanted some of the Christmas story that good mojo, that was our goal. We were half joking saying maybe this will be like "Christmas story" like every year you'll watch it. Reporter: Let the binge-watching begin. For "Good morning America," Chris Connelly, ABC news, los Angeles. We've got Peter Billingsley here with us right now and, Peter, this "20/20" special, it goes behind the scenes, classic holiday S we all love and you were in "A Christmas story." Give us something we don't know. Well, there was one scene truly -- I'll give you something I never talked about before. One scene that never made it to the movie. A huge fantasy scene there was a lot of those in the film but there was a big one in outer space and ralphie saved flash Gordon in a huge space scene but it was ultimately too much for the movie. It was cut and unfortunately it was before DVD so it's lost forever. I think there's one still out there if you deep dive on the internet you can find me with me in a silver little set of shores which isn't too flattering. I'm going to look for that. You put it on my radar. A lot of others right now in the movie you wanted a red Barron bb gun. A red rider bb gun. So growing up, was there something that you wished for ace kid. I wanted a metal detector and was convinced I would find buried treasure and leave all the acting behind. It never worked out though. It never worked out but you did pretty well for yourself regardless. Any scoop from the special. There is, you know, it was really exciting to go down and talk to these filmmakers and stars about their films. They're so passionate about it. It was not a chore for them and one pretty "The school of greatness," Bryan glazer from "Grinch" said the makeup was seven hours to put on for him. He called a friend in the CIA who has techniques that -- to deal with people who had GOP through torture and had to bring him in to consult with Jim for 48 hours so he could learn to put on the makeup. A lot of the inside stories you learn. Some of the sacrifices these guys made but ultimately they love the flips and was a joy to talk about them. I think they'd give us a greater appreciation of all these films we watch during probably the most joyous time of the year. Thanks for bringing it. Appreciate it. Good to see you, buddy. See "20/20"'s light, camera, Christmas inside holiday movie classics tomorrow night at 10:00 P.M. Eastern right here on ABC.
This transcript has been automatically generated and may not be 100% accurate.