Cameo appearances are common in Comic book movies but there haven't been many occasions where the director was a part of it. Marvel Studios' Avengers: Endgame had one such brief scene featuring director Joe Russo in the opening minutes but that was not the only instance when the helmer was involved in an on-camera scene.

Surprisingly, Joe Russo's cameo in Endgame became a platform for LGBTQ as he played the first openly gay character (in the MCU). However, there was also a day on set during filming when Joe was a stand-in for Thanos played by Josh Brolin. As reported by Comicbook, Avengers: Endgame star Karen Gillan, who appears as Nebula in the MCU was recently at Comic-Con Paris, where she revealed her funny on-set memorable moment.

The actress was to film a scene opposite to the Mad Titan but Brolin was not available to film his part on the day. Fortunately, the director stepped in as the substitution holding cardboard of a Thanos' headpiece design. Here's what Gillan had to say:

"You know what I love? It's a funny story about Joe Russo. So when we were filming Endgame, we didn't have Josh Brolin there for my scenes with Thanos, so Joe played Thanos," Gillan said with a laugh at Comic-Con Paris. "It was funny to sort of be in the scene, acting with one of the directors of the movie, and he was just wearing his own clothes, and then he had a stick with a big Thanos cardboard picture sticking into the air so that I would look at the right height. I was like, 'This is surreal.'"

Quite a few directors in Hollywood have appeared on-camera to perform scenes for a cameo. In the superhero movie genre, Director Zack Snyder has cameos in his projects like Watchmen, Wonder Woman and Justice League (scene cut from the final cut) but the scenes are so brief that they are hard to notice without a pause. Marvel director Taika Waititi went one step ahead and included himself as a supporting character known as Korg for Thor: Ragnarok. The director is also reprising the role for "Thor: Love and Thunder."

Avengers: Endgame, a culmination of the entire Marvel Cinematic Universe is the biggest ensemble movie to the date. A movie that involved over 36 actors to portray their Marvel counterparts is likely to have more such "surreal" memorable set moments. Hopefully, fans learn more about it in the future.