By now, you’ve probably heard that the man behind some of your favorite comic book superheroes, Stan Lee, passed away on Monday at the age of 95. Lee is a legend in the comic book world for collaborating with artists like Jack Kirby and Steve Ditko to create some of the most recognizable superhero stories of all time under Marvel Comics. Without Lee’s creative genius, characters like Spider-Man, Iron Man, Thor, Black Panther, the Incredible Hulk, the X-Men, and numerous others wouldn’t have come to be.  

While they originated in the pages of comic books, Lee’s characters are bigger than ever now that many of them inhabit the massively successful Marvel Cinematic Universe. You’d be hard-pressed to find someone who hasn’t seen at least one of the Avengers films, or who doesn’t know what happens when the Incredible Hulk gets angry.

In the wake of Lee’s passing, countless people—including many of the actors who play parts in the MCU—shared heartfelt tributes to the legendary storyteller, remembering him for his kindness, enthusiasm, and creative genius. Here are some of the touching posts that pay tribute to the comic legend.