Joe Ruby, the mind behind “Scooby-Doo,” has died at 87 of natural causes. The renowned cartoonist co-created the popular show more than 50 years ago and oversaw its rise to a beloved franchise.

“He never stopped writing and creating, even as he aged,” his grandson Benjamin Ruby told Variety.

In addition to bringing to life the bell-bottomed, mystery-solving gang, Ruby and his partner Ken Spears created several other series, including “Dynomutt” and “Jabberjaw.” The two wrote the first five episodes of “Scooby-Doo, Where Are You?” and then supervised the rest of the first season.

“We were worried it wouldn’t last but one season,” Spears told ScoobyAddicts.com.

But eventually, Fred, Velma, Daphne, Shaggy and Scooby became household names. The series saw several reboots and theatrical releases, including Warner Bros.’ 2002 live-action flick starring Freddie Prinze Jr. and Sarah Michelle Gellar. It was followed in 2013 with an animated film, also from Warner Bros. This year saw a CGI remake, “Scoob!” 

Ruby served in the Army and studied art before landing as an animator with Walt Disney Productions. He then went on to work in editing at Hanna-Barbera Productions, where he met Spears. At the time, the animation studio was looking for more wholesome childhood programming amid pressure from parent groups. After multiple iterations, they landed on a gang of teens who solved supernatural mysteries with their clumsy Great Dane, originally named Too Much.

“I’ve tried to figure out what made people like ‘Scooby-Doo’ so much,” Frank Welker, who’s voiced square peg Fred Jones on the series since Day 1 (and later added the voice of Scooby-Doo), told The Post last year. “I’m totally blown away that we’ve been on for 50 years. If you put a show like ‘SpongeBob SquarePants’ next to ‘Scooby’ it’s like, ‘Whoa! Time warp!’ ”

After Ruby and Spears hit it big with “Scooby-Doo,” they started their own production company with ABC in 1977, churning out hits including “Mister T,” “Alvin and the Chipmunks,” “Superman,” “Thundarr the Barbarian,” “Fangface” and “The Plastic Man Comedy-Adventure Hour.”

In later years, Ruby remained passionate about comic books and art. He is survived by his wife of 63 years, Carole, four children and 10 grandchildren.