ITV's hit talent show is back for its second episode and features a new batch of stars performing in disguise.
The new costumes were revealed in a brief teaser clip - and many fans think it contains enough clues to give away several of the big names.
One of the contestants featured in the video is the Grandfather Clock, who is heard speaking in the video.
All they say is: "Will you guess who I am?" but some fans think the clue is in the way the voice has been disgused.
Several think the voice has a "Doctor Who vibe" with some guessing it could be former Time Lord Tom Baker, who at 86 could fit in the with grandfather theme of the character.
One tweeted: "That clip who then the grandfather clock it’s Tom baker he could only have said would you like a jelly baby to make it more obvious.
"Although I'm usually wrong @ThisisDavina great tv again."
Another wrote: "Tom Baker for #GrandFatherClockMask," while others think it could be another actor linked to the hit sci-fi show.
One more character who fans think they've guessed is the Viking - with some insisted it must be a Scottish star.
Some think it could be Love Island voiceover man Iain Stirling. One tweeted: "I already can tell you Viking is Ian Stirling.
"Vikings are Scottish though there also Nordic. Scotland are Clans. Please reply and agree! I've noted this in my own detective pad!"
The other contestant attracting plenty of guesses is the Bushbaby - some think there could be an Australian connection there.
Some have guessed it could be Aussie pop star Peter Andre, while some have put forward Jason Donovan and either Ant or Dec, as the Geordie presenters host I'm A Celeb Down Under.
The Masked Singer returns to ITV tonight at 7pm.