Legendary comics artist and Spider-Man co-creator Steve Ditko has died at age 90.

The New York Police Department confirmed Ditko’s death to The Hollywood Reporter. He was found dead in his apartment on June 29, and it is believed that he had been deceased for two days before he was found. Ditko was never a fan of publicity, and he spent years avoiding the press

Ditko, along with Stan Lee, came up with the idea for Spider-Man in 1961 after Lee wasn’t satisfied with Jack Kirby’s take on a teenage superhero with spider powers.

Ditko is credited with creating Spider-Man’s costume, its red and blue design, and the web shooters. He also helped create a variety of classic Spidey villains, such as Green Goblin, Doctor Octopus, Sandman, and the Lizard.

Ditko also created Doctor Strange two years later in 1963, and shortly thereafter parted ways with Marvel Comics and Lee in 1966.

Spider-Man would go on to become arguably the most indispensable and recognizable character in the Marvel universe, and Doctor Strange a member of its permanent pantheon. The adventures of both have been turned into blockbuster films, and both had essential roles in the recent “Avengers: Infinity War.”