Lee created several characters such as Spider-Man and Fantastic Four. Unknown to him, these "characters" actually existed in various forms in alternate universes.
Spider-Man so successful that it was even made into a television series. The actor who played Spider-Man/Peter Parker was taken by the interdimensional being Madame Web to help in the attack on Spider-Carnage, without Stan's knowledge. After the dark wall crawler was defeated the actor then took a real version of Spider-Man to his dimension to meet Stan Lee.
The actor Spider-Man then introduces the real Spider-Man to Stan Lee, who thinks he’s gone crazy. After Spider-Man takes Lee web slinging, he states that he’s always wanted to experience real web slinging and that Spider-Man has changed from a kid questioning his role as a hero, to a man who fully understands his true purpose in this world. After they arrive at the top of a building, Madame Web comes and takes Spider-Man home. Stan Lee then wonders how he’s going to get down from the rooftop. He jokingly remarks, "Maybe the Fantastic Four will come and get be down."
He also helped people in his universe understand the language of the Skrull.
In the original February 7, 1998, broadcast airing of the Superman: The Animated Series episode "Apokolips... Now! Part 2" on the Kids' WB programming block, an animated Stan Lee was visible mourning the death of Daniel "Terrible" Turpin, a character based on his longtime Marvel Comics collaborator Jack Kirby. This shot was later modified to remove the likeness of Lee and other of background Marvel characters when the episode was released on DVD