J.J. the bully learns a valuable lesson in "Lou." Pixar

Pixar's "Lou" is nominated for best animated short at the 2018 Oscars.

INSIDER spoke with director and writer Dave Mullins about the five-year journey to bring "Lou" to theaters in front of "Cars 3."

The short was inspired by the feeling of being the new kid at school.

At one point, they considered making the main character, Lou, the short's villain.

A lot of the Easter eggs in the movie are nods to his family. A little girl is designed around his daughter when young.

Mullins is currently working on "Incredibles 2."

The 2018 Oscars are Sunday and among nominated shorts and films is "Lou," one of the latest Pixar animated shorts that played in front of "Cars 3."

It follows an anthropomorphic creature, Lou, who is made out of items in a lost-and-found box in a playground. Through the six-minute short, he helps a young bully, J.J., stop stealing from other kids and, instead, inspires him to start reuniting all of the kids with their missing belongings.

Ahead of the 90th annual Academy Awards, INSIDER spoke with "Lou" director and writer Dave Mullins who has been at Pixar since 2000 as an animation supervisor and animator on movies including "The Incredibles," "Finding Nemo," and "Monsters Inc." He's currently working long hours on "Incredibles 2."

INSIDER spoke with Mullins about bringing "Lou" to life over five years and how it serves as a homage to his father. Mullins also shared some Easter eggs you may have missed during a first watch, and his advice for artists hoping to break through into the business.

A short film five years in the making

J.J. steals a football and other items from kids on the playground. Pixar

Mullins started pitching short ideas at Pixar around 2005. In that time, he estimates pitching four or five different ideas. Of those ideas, one came close to being made, but never came to fruition.

When he pitched again in 2012, he went in with the idea of making a more personal film and thought of his childhood.

"I moved around a lot and there's that feeling you get when you're the new kid at school, you either want to hide from people, or you feel like people don't see you And I thought, 'You know, that would be a really cool character, if you take that negative experience and put a positive spin on it. What if there is was a character that could hide in plain sight at school? What would that be?'" That led Mullins to drawing up a bunch of characters, and that led to Lou and the lost and found box. "The thing I really liked about the lost and found box was that it has this built-in sense of purpose, which is basically it's meant to collect things that are lost, and give them back to their original owners," he said. The lost and found box from which Lou emerges. "L," "o," and "u" are the three letters missing from the box. Pixar Part of Mullins' excitement came from Pixar's penchange for anthropomorphic characters and bringing objects to life, such as in "Toy Story," but never an amalgamation of them. He drew pages of different versions of what Lou could look like imagining him as everything from a caterpillar to a two-legged guy and a blob. "From a design standpoint, as long as it's the two baseballs with buttons for eyes, and the hoodie's in there for a mouth, it's Lou," he said. "Once I had that character, I started thinking about, 'Well, [the] story is conflict, and what's the best foil for a character like this?' And it led me to the bully character. And then we had to really start digging into what makes a bully tick, and why they do what they do, and that's where the film really started to quickly come into shape." The bully, J.J., comes face to face with Lou. Pixar

Mullins and a team, which included producer Dana Murray, worked on the six-minute short in bite-sized chunks over the next several years. Though "Lou" was approved to be made in 2012, it was while Mullins was supervising animation on "The Good Dinosaur."

So the team worked on the short when they could in between major studio projects like "Coco" and "Inside Out."

"I had to finish working on 'The Good Dinosaur,' so we went on pause for like nine months. And then I got to work on Lou ... for about six or eight months there," said Mullins of the timeline for "Lou." "Then I went to work on 'Inside Out,' and then we came back and we did some pre-production [on "Lou"], and then I went to work on 'Coco' and 'Cars [3],' and then finally finished the film."

In that time, Mullins says while he received some notes from the Pixar brain trust, not a lot changed from the original story.

"Once I found the story that is on screen, I was locked into that. I knew that that's what I wanted to make," said Mullins. "I wanted Lou to be a good guy, I wanted this bully to terrorize these kids and Lou [to] force him through attrition to basically become a better person, and by doing that he actually gets what he really wants, which it wasn't stealing all this stuff. He just wanted attention." "Lou" could have been completely different The production team envisioned Lou briefly as a character who stole from the kids. Pixar Lou's a good guy in the finished version of the short, but Mullins said there was a time when they played around with him as the villain. He would have stolen items from the kid on the playground. But, in the end, it never felt right. "I think the story could have worked the other way. But just not the way I wanted it to work. I really liked Lou as this guardian," said Mullins about testing "Lou" from an alternate perspective. "The logic of the lost and found box is they are meant to collect things and give things back. To me, that was such a bullet-proof idea that I felt like you couldn't really mess with that. I felt like that was the secret sauce of it." Flipped, the story may have come across a bit different. "When you have Lou as the mean character, it makes this kid be the brunt of all this ill will, and it's hard to make a character like that likable," explained Mullins. "If you want Lou to finally give himself away at the end and make that sacrifice ... I think it's better having a good character that gives himself away to teach another character something. There's something more rewarding about that for me personally."

An homage to his father

At the end of the six-minute short, there's a small tribute you may have missed. Next to a tiny football are the words, "For Dad."

At the end of "Lou" you'll see a little note for Mullins' father. Pixar

"My dad had colon cancer, and he fought it for about eight years, and in the last year of making the film, we lost him," Mullins said. "That was kind of tough, right in the middle of production, dealing with that. And my dad and I were really close." The football is a nod to his father and the bond that brought father and son together. "I was a skate punk growing up, I liked punk rock and metal and skateboarding and D&D [Dungeons & Dragons]. And my dad was captain of the football team. He loved football and he watched the Cowboys," said Mullins. "The thing where my dad and I always met in the middle was, we loved movies. We'd watch movies together." "I had the football in there as kind of an homage to him," he continued. "The thing that J.J. bullies these kids with early on in the film and then ultimately at the end when he gives it back, it's a thing that brings him back into the fold and kind of humanizes him. I just thought that was a nice touch that worked from a sentimental, personal standpoint."

Easter eggs you may have missed the first time around

If you watch any Pixar movie or short, then you'll know there are hidden references to other films or even some more personal nods. "Lou" is no different.

"I didn't do a ton of homages to other films. Mostly it was just back to my own family," said Mullins, who listed off a bunch for us.

The classroom door numbers are a nod to his children.

The door numbers can be seen at the very start of the short. Pixar

"So the classrooms are 03, 04 and 05. My son was born in 2003, and my daughter was born in 2005," he said.

One of the characters is based on Mullins' daughter.

A still from "Lou" shows J.J. returning a lost doll to a little girl. Courtesy Pixar Animation

"The little girl that hugs J.J. and kind of snaps him out of it? That's pretty much my daughter," said Mullins. "We designed that character around my daughter, and she has this little pig doll that she's had since she was a baby that she still has."

The bully, J.J., is named after Mullins' mother.

"J.J. stands for Joyce Jean, which is my mom's first and middle name," he said. And it's stuff like that.

The "E.T." homage

Lou channels his inner Elliott and E.T. with the red hoodie. Pixar, Universal Pictures