Joe Ruby, Co-Creator of Scooby-Doo, Where Are You! , Dies at 87

Courtesy Everette Collection Scooby-Doo Where Are You!

Legendary animation writer Joe Ruby, who co-created Scooby-Doo, Where Are You!, has died at age 87.

Ruby died of natural causes on Wednesday in Westlake Village, California, Variety and Deadline reported.

A rep for Ruby did not immediately respond to PEOPLE's request for comment.

Born in Los Angeles, Ruby co-created the beloved cartoon alongside Ken Spears. The series followed teenage friends — brainiac Velma, jock Fred, fashionista Daphne, hippie Shaggy and his talking Great Dane Scooby-Doo — as they solved strange mysteries. The duo also created Jabberjaw.

Scooby-Doo, Where Are You! first premiered in 1969 on CBS and aired until 1976. It saw several reboots, film adaptations and spinoffs.

Ruby also wrote the sci-fi thriller series Planet of the Apes in 1974 and the horror film Rumpelstiltskin in 1995.

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He and Spears later founded Ruby-Spears Productions under which they created Alvin and the Chipmunks, Mister T, Superman and Thundarr the Barbarian.

Ruby also executive-produced Punky Brewster, the 1983 TV film Beauty and the Beast, and the series Rambo.

As for how he got into writing, Ruby told ScoobyAddicts.com: "There was no great awakening or such. I did some magazine cartooning years before, but never pursued it much. It was just a 'freak' opportunity that came up at Hanna-Barbera in 1959. They desperately needed people to write the short openings, closings and 30 second 'bridges' for the Huck Hound and Yogi Bear Shows, and both Ken and I started writing them on the side while we worked our regular jobs in the editorial department."

Legacy.com Joe Ruby

Of Scooby-Doo's success, Spears said in the interview that he and Ruby "were worried it wouldn't last but one season, much less 38 years."

Outside of his work in animation and TV, Ruby — who began his career under Walt Disney Productions — served in the U.S. Army, Deadline reported.

He is survived by his wife, Carole, and their four children.

Hanna Barbera Scooby-Doo, Where Are You!

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Following news of his death, several fans paid tribute to the late star on Twitter.

"RIP Joe Ruby, co-creator of Scooby-Do0, Jabberjaw, Captain Caveman & several others. Watching old VHS tapes of those guys and tracking down clips and episodes on YouTube was a huge part of my childhood," one fan wrote.

"Salute to one-half of the OTHER greatest pairing in Saturday morning history. The team of Joe Ruby and Ken Spears worked on so many shows at Hanna-Barbera before breaking out and launching their own studio," another said.

"RIP Joe Ruby, co-creator of Scooby-Doo and co-founder of Ruby-Spears. He may be gone now but he co-created something special that will live beyond him. Ruby certainly had a lasting impact on me and no doubt countless others with his group of meddling kids & their talking dog," a different fan tweeted.