RIP Stan Lee (1922 - 2018)

Legendary writer, editor, and publisher of Marvel Comics, Stan Lee has died. 

Lee created or co-created Black Panther, Spider-Man, the X-Men, the Mighty Thor, Iron Man, the Fantastic Four, the Incredible Hulk, Daredevil, Ant-Man, Dr. Strange, and countless other characters.

While their publisher, Marvel produced comic adaptations of The Muppets Take Manhattan, Muppet Babies, The Dark Crystal, Labyrinth, and Fraggle Rock. 

Lee was also instrumented in setting up Marvel's animation studio which produced the original Muppet Babies cartoon. 
Over the last decade, Marvel's films have become massive cultural milestones, and most have featured a cameo by Stan. Before appearing in mega blockbuster films, Lee appeared in the Muppet Babies episode "Comic Capers."

According to Muppet Wiki: "After Baby Rowlf and Skeeter enter the Spider-Man newspaper strip, Lee appears, hovering over a drawing desk, and takes the kids to task: "Don't you know there's only one Spider-Man?" Rowlf is apologetic ("Sorry, Mr. Lee"), but Skeeter accidentally releases a stream of webbing at Stan, coating his head with it."

The Muppets and Sesame Street have spoofed and also referenced by Lee's creations many times. Muppet Wiki has a full list, but you can take a look at a few below:  

You can read more about the "Excelsior" Stan Lee at The Hollywood Reporter. He was 95.