The newest surprise at Fox’s “Masked Singer” isn’t tied to an appearance by a mysterious celebrity.

On Wednesday night, the popular reality-competition program will bring an advertiser into its format for the first time since launching in 2019. From the opening shot to the end of the contest, “Singer” will utilize characters and other trappings from Universal’s new “Trolls Band Together” movie, slated to open on Friday. “Singer” panelist Ken Jeong will even be spotted wearing a colored wig to make himself look more like one of the creatures in the animated film.

Some TV observers might be astonished to learn that the series is accommodating an advertiser at all. Unlike predecessors such as “The Voice” and “American Idol,” “Singer” has never indulged in on-screen product placements from sponsors such as Coca-Cola, Ford or Starbucks.

“There has always been a feeling that this show is a little more crazy and a little more unexpected than a traditional reality show and it lives in its own world,” says James Breen, the series’ showrunner, during an interview. “That’s why we have resisted just doing a very ordinary, very obvious product placement.” Producers in the past have helped to create “Singer”-related advertising for sponsors including a digital series of exit interviews for Hyundai and a commercial for the movie “Scoob,” but have not brought such elements into the program itself.

“Trolls” plays right to the key “Singer” crowd, which typically consists of kids and parents watching together, says Suzanne Sullivan, executive vice president of advertising sales for Fox Entertainment. The show is the most-viewed entertainment program among kids between two and 11, according to Nielsen. Universal is counting on the nature of the program — many fans prefer to see the results as they air, not streamed later at moments of their own choosing — to help it draw consumers to the box office. Even so, “Masked Singer” does stream on Tubi and Hulu.

“This is why advertisers continue to go to broadcast TV, to get that scale” says Sullivan during an interview. “You can’t aggregate that as quickly in streaming.” She says Fox typically seeks between $75,000 and $100,000 for a 30-second ad in “Masked Singer,” and notes Universal will buy commercials to go along with its “Trolls” escapade. Universal has been one of the biggest-spending advertisers in “Singer” in 2023, peeling off more than $1.05 million for the show in 2023, according to data from ad-tracker Vivvix.

Accepting “Trolls” into the world of “Singer” came about largely because Universal, the movie studio that is part of Comcast’s NBCUniversal, inquired about the possibility last spring, well before the next season of the show had gone into production, says Sullivan. That allowed producers to build an episode around the movie without forcing various elements or appearances. “We have had, over the years, many, many advertisers that have come to us and wanted to do ad integrations” in the show, she says, “and for one reason or another, it just never worked out. This time it did.”

Linear TV spending has declined for “Singer” in recent months, as it has for many programs in traditional distribution windows. Advertisers spent approximately $63.7 million on the series in 2022, according to Vivvix, compared with nearly $123.8 million a year earlier — representing a nearly 50% decline. The average cost of a 30-second spot in 2022 came to $93,675, compared with $113,877 in 2021, a dip of about 18%.

“Trolls” mainstays Poppy and Branch will take the show’s stage as parent company Fox Corp. is betting heavily on the power of live TV to draw both viewers and sponsors. Ever since Fox’s controlling Murdoch family sold the company’s cable and studio assets to Walt Disney in a 2019 deal valued at more than $71 billion, the slimmed-down company has focused most intently on programming meant to be watched by big simultaneous crowds. Sports programming and Fox News Channel get the bulk of the company’s attention, but the Fox broadcast network plays as well when it mounts unscripted and game-show programming. To keep audiences coming back to linear TV, Fox has declined to put its sports portfolio, including its prize Sunday-afternoon NFL games, on streaming venues.

“We don’t envision having significant live sports on Tubi,” Fox CEO Lachlan Murdoch said earlier this month during a call with investors.

Producers at “Singer” have treated “Trolls” much like other themes that the show has embraced. “Masked Singer” recently worked with Warner Bros. Discovery to incorporate elements from the “Harry Potter” franchise into the program, though the appearance was organic, not because of a paid placement. Working with “Trolls” has some benefits, adds Breen, including use of the characters and access to some of the new songs in the movie.

In the streaming era, when reaching big swaths of consumers has become more difficult, Fox’s Sullivan is seeing more interest in weaving marketers into programs in a bigger way. “There is more demand to do integration partnerships than we have had in the last two or three seasons,” she says. “I think advertisers are realizing that these tried-and-true partnerships, while they are not easy to execute, are worth the time and effort.” Yes, she adds, “Singer” is open to other offers.