Toymakers have found inspiration on the toilet.

A wide array of poop-themed toys popped up in various booths at this year’s International Toy Fair, from large toymakers like Mattel Inc. to smaller ones like Poopeez.

Hasbro Inc. HAS, -0.62% lets players step on a “molded compound” in the shape of a poop emoji with its game Don’t Step In It.

Mattel Inc. MAT, -1.68% had Flushin’ Frenzy, which comes with a toilet and plunger, and has players flipping smiling scat in the air.

Spin Master Corp. TOY, +2.80% presented Flush Force, in which kids can “discover” characters in a toilet using “flush-and-reveal” technology.

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“Poop is a trend,” said one rep while touring a booth.

The toys are part of what a Spin Master rep calls a “gross category” that has caught on in the toys and gaming space. The group also includes the company’s Dr. Pimple Popper, that asks players to help Pimple Pete pop his zits without disturbing the huge pimple on his nose, which reps at the booth had filled with liquids like water and milk.

Thankfully, other toy trends from previous years, like a focus on STEM (science, technology, engineering and math) and coding, interactivity and storytelling also made a strong showing across the trade show floor.

Toymakers are hoping to take advantage of the element of surprise, with such things as versions of the popular Hatchimals brand that do not pre-announce what will come out of the egg shell before it has hatched.

Collectibles of all kinds were also on display, with Mattel’s Hot Wheels celebrating its 50th anniversary. Mattel calls the cars the “first collectible.”

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U.S. toy sales grew 1% in 2017 to $20.7 billion, according to the latest numbers from The NPD Group. Hatchimals and Pokémon were among the most popular.

“As evident by the sales success of collectibles, lower-priced toys were in many cases a substitute for higher-priced ones,” said Frédérique Tutt, NPD’s global toys industry analysts, in a statement. “However, with higher-priced toys needed for market growth, this should be an area of focus for the industry.”

There has been some disruption in the toy industry caused by Toys R Us’ bankruptcy filing and chatter about a possible Hasbro-Mattel tie-up.

Shares of Hasbro, whose toy brands include the Disney Princess line and Monopoly, are down 1.5% for the past year.

Barbie parent Mattel has seen shares fall 35.4% over the past 12 months.

And Spin Master, whose brands include Luvabella and Etch A Sketch in addition to Hatchimals, has seen shares climb 67.4% for the last year.