"Now just going to interrupt you here for the 'Nuff said,' last appearance during his lifetime, of Stan Lee. Who had a grand old time dressing up as his former self," co-writer Christopher Markus says on the Endgame commentary of the late Lee, who appears as an anti-war hippie behind the wheel of a muscle car in 1970 New Jersey.
"And who'd been Lola'd [de-aged by LolaVFX], right? That was the idea," added co-writer Stephen McFeely.
"Yeah, he was de-aged there so it looks more like Stan in that time period," said director Joe Russo. Added Markus, "And there is that famous picture of Stan in the '70s wearing that outfit with that hair."
"This was his final cameo that was committed to film," Joe earlier told ComicBook.com.
"It was always... I grew up as a Marvel fanatic, and watching the Spider-Man cartoon show as a kid with his voice in it. I think anything that affects you as a child really affects you as an adult, sticks with you. So when he would come on set, and we'd hear his voice, it's sort of Pavlovian in a way, where you just become a child again. The whole crew would be like that. People were always... All these movie stars on set every day, and then Stan would show up, and it was just like people were kids all over again."
Lola's Trent Claus told ComicBook.com Lee's de-aging in the 1995-set Captain Marvel was minimal, but in Endgame, "We had to go back 45 years, so it was a pretty sizable amount."
"The work that we do, we don't create a CG replication of the actor. We use the actor that's actually there on screen, so we were actually modifying the actor in the performance that was there on set as opposed to re-creating something new," Claus explained.
"So, we have to treat each and every frame like a painting, where you're working with light and shadow, and form, and composition, and things like that to accomplish the goal."
Using a variety of photos collected from Lee in the '70s for reference, Claus and his team of special effects artists utilized the same digital makeup seen in Ant-Man and Captain America: Civil War.
"In addition to that, you have to rely on the artist's knowledge of anatomy, the changes that happen to humans over time," Claus added.
"The physiological changes in the skin and the muscles, and the mechanics of the expressions that you make in your face, and also the body, the posture and the build of the body changes over time. All those things have to be taken into consideration."
A featurette looking back on Lee's many MCU cameos, "Remembering Stan Lee," is included among the Endgame home release special features.
Buy or Pre-order Avengers: Endgame: