Gary Friedrich, the co-creator of Marvel’s “Ghost Rider” and “Son of Satan”, has died at 75 of complications from Parkinson’s Disease, reports Heat Vision.

The writer was a childhood friend of Marvel writer and editor Roy Thomas, who announced the death of Friedrich, shared on Facebook by Friedrich’s Marvel contemporary, Tony Isabella. According to Thomas, “[O]ne of my oldest and dearest friends, Gary Friedrich, passed away last night, from the effects of Parkinson’s, which he had had for several years. That and his near-total hearing loss had left him feeling isolated in recent years, and his wife Jean seems content that he is finally at peace.”

Writes the site:

Thomas recommended Friedrich as a freelancer to Charlton Comics editor Dick Giordano in the early 1960s. After breaking in with stories for the independent publisher’s romance comics line, he moved on to work with Sam Grainger and Steve Ditko for Charlton’s superhero comics, including dialoging the first appearances of the Blue Beetle.

At the same time, Friedrich had started writing for Marvel, initially providing stories for its western line including Rawhide Kid and the western incarnation of Ghost Rider. From there, he branched out into the publisher’s war comics, including issues of Sgt. Fury and his Howling Commandos and Combat Kelly and the Deadly Dozen, as well as occasional contributions to its superhero line throughout the late 1960s.

By far his most well-known contributions to Marvel come in its nascent horror line of the early 1970s; in addition to his work adapting Mary Shelley’s novel into comics as Monster of Frankenstein with artist Mike Ploog, the two collaborated to create Johnny Blaze, the motorcycle-riding demon known as (the second) Ghost Rider in 1973. The first issue of Blaze’s series also introduced Daimon Hellstrom, also known as the Son of Satan, who would go on to become a recurring character throughout the Marvel Universe in subsequent years.

Friedrich’s part in the creation of Ghost Rider would be a point of conflict between himself and Marvel in later years, with the writer filing suit against Marvel, Sony Pictures, Columbia TriStar Motion Pictures, Hasbro and other companies in 2007 alleging that the character had been exploited without his permission, and that both film and merchandizing rights had reverted to him in 2001. The case was ruled in Marvel’s favor in late December 2011, and upon appeal, the two sides settled in 2013.