Clay Martin Croker, the animator and voice actor best known for playing Zorak and Moltar on "Space Ghost Coast to Coast," passed away this morning. He was 54.

His passing was reported by numerous sources, and confirmed by Adult Swim, but no cause of death has been announced.

RIP C. Martin Croker pic.twitter.com/Ol6RNHhs60

— [adult swim] (@adultswim) September 18, 2016

An Atlanta native, Croker began working for Turner Broadcasting System in the early 1990s as an animator for TNT's "TNT Toons" promos. He later served as animation director of "Space Ghost Coast to Coast," Cartoon Network's first fully produced original series and, in many ways, the progenitor of Adult Swim.

Hosted by 1960s Hanna-Barbera superhero Space Ghost, "Space Ghost Coast to Coast" was a surreal talk show parody in which real-life celebrities were awkwardly interviewed, between disruptions by his foes Zorak and Moltar, who were forced to work as band leader and director/producer, respectively. Croker has been widely credited with the idea of include Space Ghost's longtime enemies as part of the show.

Croker later reprised his role as Zorak on the spinoffs "Cartoon Planet" and "The Brak Show," and voiced Dr. Weird and his assistant Steve in the first two seasons of "Aqua Teen Hunger Force" and in the feature "Aqua Teen Hunger Force Colon Movie Film for Theaters."