The characters include The Gremlin, The Snow Owl, The Crocodile, The Giraffe, The Broccoli, The Popcorn, The Seahorse, The Jellyfish, The Mushroom, The Dragon, and The Sun.
There will also be a few characters who seem to be new iterations of previous costumed creations, including Whatcha Macallit (undoubtedly a cousin to season 2's Thingamajig), Squiggly Monster (who might be part of Monster and Miss Monster's family), and Baby Alien (who might be the offspring of The Alien from season 1).
The promo also revealed that the upcoming season is set to kick off Sept. 23.
While the teaser only gave three brief glimpses of the costumes -- which were so quick and close up it's hard to guess which characters they represent -- the show did tweet out a first look at The Crocodile.
It appears the show's main panel of "celebrity detectives" -- Ken Jeong, Nicole Scherzinger, Robin Thicke and Jenny McCarthy -- will all be returning for season 4, and host Nick Cannon will again be taking the stage as emcee.
According to a press release from Fox, the celebs competing this season "have sold more than 281 million records worldwide, appeared in more than 5,475 episodes of television and 151 films, appeared in five Super Bowls, have four stars on the Hollywood Walk of Fame," and one of them appeared on the list of Time's 100 Most Influential People.
Fox will be airing a special season 4 sneak peek live coast to coast on Sunday, Sept. 13 at 8 p.m. ET/5 p.m. PT. The season premiere kicks off Sept. 23 at 8 p.m. ET/PT on Fox.
For more on the exciting third season of The Masked Singer, which came to an end May 20 with a surprising finale, check out the video below.