Old-school Dungeons & Dragons fans are mourning the death of David Trampier, a once-famed fantasy artist who contributed to the game’s original allure—only to mysteriously disappear from the public eye in the 1980s.

Trampier, 59, died on March 24 at a nursing and rehab facility in Carbondale, Illinois. Scott Thorne, owner of Carbondale gaming store Castle Perilous, had been in touch with the elusive Trampier before his death and wrote in a blog post that the artist was recently diagnosed with cancer and suffered a stroke.

In the late 1970s, Trampier’s paintings and drawings peppered the manuals and modules for Advanced Dungeons & Dragons, the first edition of the groundbreaking role-playing game. He also authored Wormy, a long-running comic strip in the D&D magazine Dragon, which joked about RPGs from the monsters’ point of view.

Trampier’s best-known work is the 1978 cover of the first-ever Player’s Handbook—the one manual every D&D player must own. It depicts adventurers cleaning up after a successful battle against lizardmen; men pry giant gems from the eye sockets of a demonic idol, a tough guy wipes lizard blood off his sword and warriors consult a map leading to their next conquest. In a 2011 survey of Trampier’s work, fantasy author Saladin Ahmed praised the cover as “arguably the most iconic piece of art in all of RPGdom.”

A house artist at TSR, the original D&D publisher, Trampier also worked on the company’s other pioneering RPGs. Outside of TSR, he co-created a fantasy board game, still available in a newer edition, called Titan.

In 1977, Trampier’s Wormy began its 11-year run in Dragon. Probably Trampier’s most beloved work, its colorful style and country-tinged humor made it something like a D&D version of the classic comic Pogo.

Wormy abruptly disappeared without announcement or explanation in 1988—and so did Trampier. Determined fans were unable to track him, and his work never appeared in any publications again.

Trampier’s final appearance in the public eye only added to his mystery. A 2002 Southern Illinois University newspaper article profiled Trampier as a cab driver in Carbondale, and the student reporter either didn’t know of Trampier’s artistic past or agreed not to mention it. She described him as carrying homemade cigarettes in a box marked “Outlaw” and telling a story about an atheist and a Baptist preacher arguing in his cab.

“This job suits my personality. It’s continually dealing with different people,” Trampier told the reporter.

According to Thorne, Trampier had dropped out of the RPG industry over a bitter dispute with TSR about publishing a Wormy collection. At Thorne’s urging, Trampier was apparently on the verge of returning to the fantasy world. He was slated to appear at next month’s Egypt Wars gaming convention in Carbondale, where Thorne hoped Trampier would cross paths with a publisher interested in issuing the Wormy book.

“Unfortunately, that won’t happen now,” Thorne wrote.

In the early stages of what appears to be a growing memorial movement, some of Trampier’s original artwork will be displayed at Egypt Wars. Photos of select pieces can be seen on the Castle Perilous website.