Jean Giraud, best known by his pen name Moebius, died on Saturday after a long illness, Le Monde reports. He was 73. The French illustrator created comics set in the American West and was especially admired for his wildly inventive science fiction and fantasy worlds.

After studying at Paris’s Ecole des Arts Appliqués, Giraud published his first comics in several children’s magazines during the mid-1950s. In 1963, he created the character Mike “Blueberry” Donovan, a hard-boiled American lieutenant, who appeared in the comic “Fort Navajo,” which was co-created by Giraud and Jean-Michel Charlier. Giraud signed this series “Gir,” a pen name that he continued to use for Blueberry throughout his career. The character was based on French actor Jean-Paul Belmondo, though Moebius told Le Monde Magazine in 2010 that he also drew inspiration from Charles Bronson, Clint Eastwood, Arnold Schwarzenegger, and even Keith Richards when developing Blueberry, and he also cited directors Sam Peckinpah and John Ford as influences for his “movies on paper.”

In December 1974, Giraud co-founded the French comics magazine Métal Hurlant, whose American version, Heavy Metal, was launched in 1977. For his science fiction and fantasy work, he took the pen name Moebius from the Moebius strip, a twisted circular shape described by German mathematician August Ferdinand Moebius. Moebius debuted the character Arzach in the pages of Métal Hurlant, creating a story without words, in which the hero rides a pterodactyl-like creature through alien landscapes that evoke dreams and the subconscious.

While Blueberry and Arzach remain his most famous creations, Moebius worked on a number of different publications and projects, collaborating with Stan Lee in 1988 and 1989 on issues of the Silver Surfer and contributing storyboards and design elements to science fiction films including “Alien,” “Willow,” and “Tron.”

In 2010, Paris’s Cartier Foundation showed a retrospective of Moebius’s work. “My drawings are not about dreams during sleep over which no one has any control,” the artist told ARTINFO France at the time. “They are lucid dreams in which everything can appear: childhood memories, fleeting moods, anger, laziness. It’s very hard to identify exactly what is at work in these dreamworlds. While science fiction is based on prediction, I have progressively abandoned this notion to create hybrid drawings in the borderland of dreams.” 

Click on the slide show to see work by French comic book artist Moebius.