SPOILER ALERT: Do not read ahead if you have not watched the Season 10 season premiere of "The Masked Singer," which aired Sept. 10 on Fox.

"The Masked Singer" kicked off its 10th season on Sunday night with a special episode — and a lotta Lovato. Demi Lovato as "Anonymouse" was the first celebrity unmasked this season — although there's an asterisk there. Lovato didn't appear as part of the competition (otherwise they absolutely would have continued into future weeks), but as a one-off.

Lovato, of course, got their start at Disney — a.k.a. the Mouse House — via the Disney Channel movie "Camp Rock" and series "Sonny with a Chance." So the "Anonymouse" character itself was most definitely a hint to Lovato's identity under the mask.

Lovato opened the show with a strong take on "What About Love," as originally performed by Heart. "Just like Michelle Obama, Oprah and Angelina Jolie, I'm on one special list: Time's 100," they gave as Anonymouse's first clue to their identity.

Here was the second clue: A slab of concrete that said "Anonymouse." Said Lovato, still in character: "This is a literal concrete clue. My acting career has cemented me as one talented mouse."

And then there was the Anonymouse's clue package voiceover: "When I found out that 'The Masked Singer' needed a mystery guest to celebrate their milestone 10th season, I knew I was the right rodent for the job. I started working young. But my big break came when I was able to showcase my voice. When my future was looking bright on the outside, I struggled with demons on the inside. The more I pushed, the more I felt myself slipping away. I was trapped on a path of wrong decisions. And eventually, I hit rock bottom. But that was the wakeup call I needed to finally realize, I had so much more life to live. Now, I've made it my mission to seek out joy wherever I can. And that's exactly what I'm doing here. It's about time I stop by. You all have been guessing me for the past nine seasons! But when this mask comes off, you'll see, there's no mouse like me."

Among the early names thrown out by the panel: Miley Cyrus, Alicia Keys, Christina Aguilera, Ariana Grande, Lady Gaga, Jennifer Hudson, Kelly Clarkson, Pink and Lovato.

Back for Season 10 are host Nick Cannon, alongside panelists Jenny McCarthy Wahlberg, Nicole Scherzinger, Ken Jeong and Robin Thicke.

For Lovato as Anonymouse, Thicke, Scherzinger and McCarthy Wahlberg all got it right. Jeong went with Lady Gaga.

Lovato's appearance was also timed to the release of her new album, "Revamped," on Sept. 15, for which she has re-recorded 10 of her songs as rock versions. Lovato will also be seen this Tuesday performing live on the MTV Video Music Awards. (She's nominated for best pop and video for good.)

"The Masked Singer" will include a new format this season, with three groups followed by Battle Royale semi-final episodes. The season also includes the return of Wild Card contestants, with one Wild Card introduced to each group, and the "Ding Dong Keep It On Bell" is back in the Battle Royale semi-final episodes, where the judges can choose to save one contestant from elimination and move them directly to the finale.

With sixteen total celebrity singers, Season 10 features new costumes including "Donut," "Anteater," "Hawk," "Hibiscus," "Diver," "Gazelle," "Royal Hen" and a life-size "S'More." Also returning to mark the show's 10th are celebrities who have been previously unmasked since the show began.

The season's themed episodes will include a tribute to Elton John; a "Trolls Night" tied to the November release of DreamWorks Animation's "Trolls Band Together"; a "Harry Potter Night" airing the week of Halloween; "NFL Night"; "One Hit Wonders"; "Disco"; "2000s Night"; "I Wanna Rock"; and "Soundtrack of My Life."

Here were the other mask-free celebrity performances on Sunday's special episode:

Michelle Williams (Butterfly, Season 2) and Rumer Willis (Lion, Season 1): "(You Make me Feel Like) a Natural Woman," by Aretha Franklin.

Victor Oladipo (Thingamajig, Season 2) and Barry Zito (Rhino, Season 3), along with Scherzinger: "Meant to Be," by Bebe Rexha feat. Florida Georgia Line

Joey Fatone (Rabbit, Season 1) and Bow Wow (Frog, Season 3): "ABC," by the Jackson 5

Last spring, Bishop Briggs kept a steady flow throughout Season 9 of Fox's "The Masked Singer" — and her perseverance was rewarded with the championship. Briggs, as Medusa, won this season's top prize and was unmasked during the finale, along with runner-up David Archuleta, revealed as the Macaw.

Briggs as Medusa and Archuleta as Macaw joined Pentatonix as California Roll, Olivia Culpo as UFO, Lou Diamond Phillips as Mantis, Keenan Allen as Gargoyle, Melissa Joan Hart as Lamp, Alicia Witt as Dandelion, Dee Snider as the Doll, Christine Quinn as Scorpio, George Wendt as Moose, Holly Robinson Peete as Fairy, Alexa Bliss as Axolotl, Lele Pons as Jackalope, Malin Akerman as Squirrel, Michael Bolton as the Wolf, Grandmaster Flash as Polar Bear, Debbie Gibson as Night Owl, Howie Mandel as Rock Lobster, Sara Evans as Mustang and Dick Van Dyke as Gnome as the celebrities unmasked in Season 9.

"The Masked Singer" is produced by Fox Alternative Entertainment, with James Breen (who is also showrunner), Craig Plestis and Cannon as executive producers.