WARNING: This article contains spoilers for Avengers: Endgame.
Prior to his death last November, Marvel Comics visionary Stan Lee filmed his final MCU cameo on Avengers: Endgame, and as audiences who’ve seen the film already know, it takes place during Steve Rogers and Tony Stark’s daring attempt to retrieve the tesseract space stone and more Pym particles in 1970. Soon after the pair departs the battle of New York in 2012, a road outside of an army base is revealed, as is a car with a bumper sticker that reads “‘Nuff Said.” The car’s driver? A de-aged, rambling hippie version of Lee.
“It’s sort of the hippie era, and Stan’s cameoing as a hippie and it’s the free-love era,” director Joe Russo explained to Entertainment Weekly. “He’s saying, ‘Make love, not war!'” He and his brother, fellow Endgame director Anthony Russo, also shared a behind-the-scenes photo of Lee’s cameo shoot on their official Twitter page.
https://twitter.com/Russo_Brothers/status/1125425048834035713
“It seemed like fun when we originally had the idea, before Stan passed,” Joe continued. “Oh, what did Stan look like in the ’70s?”
While Lee was decked out in hair, makeup and costuming to answer this particular question, however, the filmmakers also employed the same de-aging special effects that previous MCU films have successfully used. These past examples include Robert Downey Jr. (Captain America: Civil War), Kurt Russell (Guardians of the Galaxy, Vol. 2), Michael Douglas (Ant-Man and Ant-Man and the Wasp), and Michelle Pfeiffer (Ant-Man and the Wasp).
(Via Entertainment Weekly)