On Friday, Dec. 28, just over a month since Stan Lee died at the age of 95, figures from Marvel joined in commemorating what would’ve been the comic book creator’s birthday.

“Happy Birthday, Stan. Thank you for everything,” a tweet from Marvel reads, accompanying an artist sketch.

Mark Ruffalo, the Hulk actor from the Marvel Cinematic Universe, wrote, “Thank you always for your vision and magic, Stan. Happy birthday.” Similar responses came from Spider-Man: Into the Spider-Verse writer and producer Phil Lord, Kevin Smith, Deadpool co-creator Rob Liefeld, and Marvel Entertainment Chief Creative Officer Joe Quesada.

“Stan Lee’s Birthday should absolutely be a holiday, a stamp, a national honor,” Liefeld wrote in a post on Instagram. “I hope it comes to pass in my lifetime.”

Lee got his start in the comics business in 1939 and went on to help craft characters like Spider-Man, Black Panther, the Fantastic Four, Iron Man, and countless others. Fans of Marvel continue to mourn his death today.

Smith shared a video from Lee’s 95th surprise birthday celebration at a steak house in Beverly Hills. “I asked ‘Are you sure it’s a good idea to throw a *surprise* party for a 95 year old?’ But it truly was: as you can see in the video, Stan made it through the surprise just fine,” he wrote on Instagram.