"Think Curb Your Enthusiasm episodes, in an hour long show, and we're all playing heightened versions, so it could be fictional, it could be non-fictional, people will have to guess," she continued. "And then we will have pop-ins, because we're behind the scenes trying to do the reboot."
As for when we might see this show happen, Spelling says "not quite yet, but it'll be 2019."
She says they've been working on this idea for "a long time," and that "almost the entire original cast" has signed on. While Luke Perry is currently on Riverdale, he'll be able to show up as a guest star when he has time.
Beverly Hills, 90210 also starred Jason Priestley, Jennie Garth, Ian Ziering, Brian Austin Green, Gabrielle Carteris, Carol Potter, and James Eckhouse for most of its run. Shannen Doherty starred for the first four seasons, and Tiffani-Amber Thiessen joined the show in season five.
Spelling was surprised that it was Ken Jeong who guessed that it was her, since he was the one she didn't really know very well.
"Jenny [McCarthy] and I have been friends for years, and I grew up with Robin Thicke. I'm like, he's gonna know it's me," she said. "The only one I didn't really know at all was Ken, and he's the one that guessed me."
Spelling was focused on embodying the character of the Unicorn as opposed to trying to throw people off that it was her.
"I had to be like, regal, but also I had my little giggle. My friends say when they look back that the shoulder shrug gave it away," she shared.
Spelling said she practiced with her kids, though they weren't allowed to come to set with her.
"It was a closed set, because they didn't want anyone to guess. If there's five little ones showing up, they might be like, who's crazy enough in Hollywood to have five kids? Tori Spelling!"
The show brought in a vocal coach from The Voice and a choreographer and gave Spelling two weeks of voice practice and six hours of choreography, and she says she even lost weight from both the practice and the fact that the costume was so hot and heavy.
"I lost so much weight. They said each week they were taking in my costume, probably because I was sweating so much."
As for who else might be unmasked on the Fox reality series, Spelling has absolutely no idea, so she'll probably be tuning in with the rest of us to find out.
The Masked Singer airs Wednesdays at 9 p.m. on Fox.