W.C. Fields once warned fellow filmmakers to “never work with animals or children.” For Jackass Presents: Bad Grandpa, Johnny Knoxville and Jeff Tremaine opted to work with both. That is, if a Jackass—with a capital J—can indeed be considered an animal.

Opening in theaters nationwide today, Bad Grandpa continues the story of 86-year-old curmudgeon Irving Zisman (played by Knoxville), a recurring Jackass character since 2001, who teaches his eight-year-old grandson Billy (Jackson Nicoll) the ways of the world on a cross-country road trip. Along the way they meet a colorful cast of characters, including a group of male strippers and a bevy of pissed-off kiddie beauty pageant contestants, many of whom take it upon themselves to confront Irving about his inappropriate behavior. Not a good idea.

Melding scripted content with hidden camera footage, Bad Grandpa is the first big-screen effort from the Jackass team to take this hybrid production approach. While premiering—and promoting—the film in Las Vegas, writer/producer/star Knoxville and writer/director Tremaine chatted with Complex about Irving's origins, bringing a kid into the Jackass fold, and pranking the public. 

How and when did the idea for Bad Grandpa come about?
Jeff Tremaine: We started talking about the possibility of spinning Irving into his own movie after the second Jackass movie, which was 2006. We threw the idea around loosely and not seriously. And then, about two years ago, Paramount asked us if we were still considering it. We hadn’t really thought about it much, but that’s when we started coming up with the idea and sort of writing the story.

The character of Irving has been a staple of the Jackass franchise for a while. Is he based on someone you actually know?
Johnny Knoxville: There are a lot of mannerisms and things from my father, but mostly it’s just a more perverted version of myself. 

How long did it take for you to get into character each day, including makeup?
Knoxville: Three hours—five hours if I wore the front and the back, where I had to spend the last two hours standing. I wrote those out of the movie after the first couple of times.

Was it always conceived as a partially narrative, partially hidden camera structure?
Tremaine: Yeah, we knew it was going to be a narrative and we definitely knew that there would be a hidden camera. We just didn’t know that the narrative was going to be as dominant as it ended up being. At first, to keep it manageable, we were just thinking of funny ideas. And then as we started developing it, the pranks were built into the story—the narrative beats were actually in the pranks.

Johnny, you and Jackson had worked together on Fun Size. What was it about him that you knew would work well for this project?
Knoxville: He’s really spirited and he’s just fearless. I knew that he was a great actor, and really cute, but I thought his fearlessness would just really bode well in doing what we do.

Jeff: When [Johnny] came back from Fun Size, he came to the office and was like, “Man, I just worked with the greatest kid. We need to do something with him.” At this point we weren’t even thinking of Bad Grandpa, we were just thinking of some Jackass ideas to do with him. And then we came up with the idea for this story and he was instantly the kid we wanted.

What are the biggest challenges—legal, production or otherwise—in creating this kind of film with a kid in a starring role?
Knoxville: The hardest thing we do is public pranks. Like Jackass, you just have to keep doing them and doing them until you find that right person or persons. I was in makeup three hours a day, so that cuts a lot of your day out. Then with Jackson, you have a very limited amount of time you can shoot with him because he’s a kid. So there were a lot of minuses going into this film. [Laughs.] We were pretty crazy to do it, but we’re really happy we did because it turned out great. We can’t wait for people to see it.

Who had the pleasure of telling Jackson’s parents that he’d be appearing in lingerie and humping a stripper pole?
Tremaine: I didn’t tell his parents about that idea. But this kid hates having clothes on anyway. He loves Speedos.

Knoxville: His parents are great. We obviously ran everything by them and they just couldn’t have been more cooperative and cool. There’s a reason their kid’s so rad and it’s because of them.

Thanks to you guys I will have "Cherry Pie" stuck in my head for the next month. I assume you only had one shot at getting all of the footage for the beauty pageant?
Knoxville: No, we did that twice.

OK, so even twice: How in the hell did you pull that off—Jackson with the choreography and staying in character, you stepping onto the stage and making it rain? How do you possibly do that in even two takes?
Knoxville: It took Jackson two months to learn all the dance routines and pull off being a little girl. Not only did he pull it off, he was in contention to win the thing! So he went above and beyond with how we thought he’d do.

And he totally embraced everything you guys threw at him?
Knoxville: Yeah. In all these interviews he’s saying, “Oh, yeah, I was nervous before.” But I think he’s putting up a front. Because he was having a ball when we did it.

Were his parents there throughout the shoot?
Tremaine: Yes, his mother traveled with us everywhere we went and was always listening in. One of the threats we had for him to behave himself was, “Hey, your mom’s listening.” He didn't believe it. He couldn’t understand that his microphone was being fed into where she was sitting.

What do you estimate the chances are that he’ll end up in therapy some day?
Tremaine: Jackson is a real character. I don’t think he’ll end up in therapy. But he’ll leave a trail of destruction behind him.

The great thing about a hidden camera project is the authentic reaction you get from the unknowing participants. But then there’s the issue of needing to get their consent to appear in the film. On Bad Grandpa specifically, was there anyone who wouldn’t agree to be in the film?
Tremaine: There were a few people who definitely didn’t want to be in our movie after we filmed them. One pageant dad in particular had a great interaction with Irving and he hated us, so we weren’t able to use it. But in general we usually make it pretty nice. We’re not out to be mean to people. We’re not trying to make people look stupid; we’re just doing stupid stuff in front of people and trying to make them look normal.

Is there a difference in the way that people react to being antagonized by a twenty- or thirty-something person versus an 86-year-old man?
Knoxville: Oh, yeah. You can get away with so much as an old man. And then to have a cute little kid with you? We had sympathy coming out all sides, and we really used it to our advantage. [Laughs.]

What are the biggest challenges in creating a film that merges hidden camera elements with traditional narrative feature techniques?
Tremaine: This movie, from a production standpoint, is a stupid idea. [Laughs.] You start off your day putting your star through four hours of makeup before you can even start shooting. And then you’ve got all the constraints of having an eight-year-old on set; there’s time restrictions and everything else. And we didn’t come up with a smart device to have a camera out, so every camera had to be hidden. That’s just how you start your day. Then you’re hoping and fishing for great reactions—you’re hoping people will behave how we planned. So, yeah, it’s a terrible idea for a movie, but somehow it worked out for us.

From a cinematography standpoint, how do you balance the need to be inconspicuous with the need to capture cinema-quality footage?
Tremaine: We used a million different cameras. When we could, we would use these big Sony F3cameras. So if we’re shooting outside we have what looks like a plumber’s van, and it’s got two or three cameras shooting out of it at all times. And they’re big cameras on tripods that you can’t see, because they’re behind tinted windows.

But then if we’re in a location like the funeral home, for instance, that funeral home had a perfect place to build a fake wall. So we actually divided the space with a fake wall that had two cameras behind it. And we brought in these people who had never been in that funeral home, so they didn’t notice anything different. Ideally, we’d build into locations and have cameras hidden, but we can’t always do that. So we have to scale it down from there, all the way to little GoPro cameras.

Do you ever have to re-create any of the scripted action in order to improve the quality of what you’ve captured?
Tremaine: A lot of times we’ll do multiple takes on different marks, so we’ll get multiple chances at doing each stunt. We also do some of our rehearsals in the same space and we roll on those, so there are some pickups in the same location, but we use very little of that.

What about the writing process? As the film is partially scripted, was that all done ahead of time or as you went along?
Tremaine: No, it was an evolving story. The basic story from the get-go was definitely about Irving forming this relationship with his grandson. But we had all these other elements that we slowly pared out as we realized what was working best, which was really Billy and Irving.
We dressed Spike [Jonze] up as a woman—he was going to be Irving’s love interest—and we shot some really funny stuff, but it sort of convoluted the story. It just got in the way of this simple story, and that’s what was working.

Knoxville: We shot so much—we’ll shoot more than double what we need. You just have to take those chances. We shot a lot of great stuff with Spike as Gloria, but we had to cut out all of those scenes because they just didn’t work for the movie. It’s the same thing with Catherine Keener, who played my wife; we got so many funny things but it didn’t work for the story and we had to cut it out. And that’s painful to do.

Without giving too much away, what was the hardest stunt to pull off in this movie?
Tremaine: There’s the bit where Johnny sits on a little rocket and launches through a window. It’s a little coin-operated toy that we rigged to launch. That was a really complicated stunt because he was flying into a store, so we had to shoot it from both inside and outside of the store. And it was a dangerous stunt on Knoxville’s part, but also dangerous because you needed people to be close enough to see it and react to it but not too close. So we had to wait and wait for the right moment. That was a really complicated one.

Did you have only one chance to do it?
Tremaine: We were actually set up to do it again, but we got it right the first time. We could’ve done it again, because there’s a lot of turnover with the customers, but then you’re at risk of people talking about it.

There were definitely a lot of complicated scenes. The beauty pageant was complicated, the funeral home was really tricky because it took us a while to figure out how we were going to populate the funeral of a woman who didn’t exist. We got creative with how we could get people to sit there for a funeral; we had our producer calling around saying, “My grandmother died and she loved gospel music,” so we got a gospel choir. We wanted some sweet old ladies, so we called a cat society.

How do you work with Charlie Grisham, your stunt coordinator? You guys obviously come in with a lot of ideas, but was there ever an instance where he really just had to say, "No way!”
Tremaine: Charlie worked with us on Jackass 3D, so he knows not to say “no way.” [Laughs.] He just helps us on how to execute it. He was in the store when we launched the rocket into the window; I had to have visual contact with him. I was hiding in a car with the cameras and he had to give me a thumbs up when we were ready to go. As soon as I got a thumbs up from him, I told Knoxville to go, who had an earwig. So you’ll see Charlie in the background of a lot of the shots just to be a safety outlet for Johnny when we’re shooting.

Do you think there’s such a thing as going too far for a great joke?
Tremaine: I’m sure there is. But those are usually the best ones.

Knoxville: We’re not mean to people; that’s not the goal. We do things in a certain spirit. And afterwards people have to be cool with it or they won’t sign. And you go in and talk to them and you hug it out afterwards. We want to make sure they’re cool with it.

Much of the film’s production team is made up of longtime Jackass contributors. What’s the key to maintaining such a longtime creative collaboration?
Tremaine: I don’t know what the key to it is. We’re just stuck together, I think.

Is there one trait that you guys all seem to share?
Tremaine: An ever-evolving bad sense of humor?

Of all the stunts you’ve performed or been a part of within the entire franchise—from television to films—which is the most memorable and why?
Knoxville: The beauty pageant is definitely one of the best things we’ve ever done, Jackass included. The strip club scene in this movie is really great. As far as Jackass, the Terror Taxi from Number Two is wonderful. Ryan Dunn sticking the car up him bottom in the first movie was great.

What’s the one stunt you’ve always talked about doing but have yet to pull off?
Knoxville: There’s a lot of good ideas floating around but I’m not going to ruin them by telling you about them. I’d rather you see them.

If you had to describe the Jackass experience in one word, what would it be?
Tremaine: Oh, god.

That’s two words.
Tremaine: [Laughs.] I can’t do it.

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