According to Rick Copp, the writer of Scooby-Doo and the Witch's Ghost, the Hex Girls were created due to his love of Josie and the Pussycats. Jane Wiedlin, Kimberly Brooks and Jennifer Hale were cast as the girls, though ironically, Hale had formed a cover band when she was 15, and covered many of Wiedlin's songs (as part of the Go-Gos band) before knowing her.
When they first started, the three actresses actually had no idea how to pronounce "eco-goth."
"We actually had to debate how to pronounce it. We were like, “Echo-goth?” “Ee-ko-goth?”" Hale revealed in an interview.
Despite some minor lashback from some religious groups, who attempted to ban Witch's Ghost from being released because they thought it promoted witchcraft, the Hex Girls were an instant success. They were such successful characters, in fact, that Warner Brothers briefly considered a Hex Girls spinoff, though it never got beyond a very early development stage.
"They had found that there was a lot of chatter about the Hex Girls from the movie, and I remember my friend Linda Steiner [then the Vice President of Development at Warner Bros Television Animation] brought me in for a meeting to talk about a spin-off series. You can imagine my excitement! Oh my god, doing a girl band series! And they wanted David and I to develop it. We talked about it, but it just never... it was one of those Hollywood meetings that never really went anywhere." Rick Copp shares.
Though it never went anywhere, all three voice actresses for the Hex Girls said that they are incredibly excited at the idea of having a spin-off series, and would be definitely interested if the series was ever picked up by a network. Here's what all three actresses have said on the matter:
Wiedlin: I absolutely think they could have their own show! Every time they could introduce a new song and they could be the defenders of the planet plus do rock concerts. It’s such an easy sell! If it happened I would be so excited. I live in Mexico, but I would totally fly back every time to LA to do the episodes. Totally, I don’t care.
Hale: I’d be there with bells on! I’d be beating down the door. I’d be 30 minutes early with coffee for everyone.
Brooks: There’s still time, right? I don’t know who to talk to – I need to call my agent, somebody needs to get the ball rolling here! We need strong characters that have their own point of view and their own perspectives, who speak their minds and aren’t stereotypical girls. I love that we’re different and that we represent all types of women, which is just so important right now. I think that definitely played a role in why people identify with them.
Some aspects of this fun fact were taken from the article "The Hex Girls: How a Fictional Scooby-Doo Rock Band Became Cult, Queer, Girl-Power Icons," which is an awesome article you should definitely check out for more info!