With inflation shrinking present budgets for families across the United States, adult toy enthusiasts are becoming an increasingly important target for the industry. According to data from consumer analytics firm NPD Group, shoppers above the age of twelve are the largest source of growth for toy sales, accounting for one out of every four dollars spent on toys.

While sales to so-called "kidults" have been growing for years, the last two years saw a significant spike. During the twelve-month period ending in September, 60% of the dollar growth seen in the toy industry was driven by kidults, despite the fact that they only account for a quarter of all sales.

"Over the last two years, most of the sales gains in the global toy industry came from the so-called kidults, teenage and adult consumers who enjoy things like playing board games, building sets, puzzles or collecting action figures," NPD's Vice President and Toys Industry Analyst Frédérique Tutt wrote.

Kidults are a particularly attractive market because they tend to be willing to spend more on toys compared to parents. These shoppers are interested in products typically designed "for kids", like Lego sets and dolls, but toy companies are also introducing new, high-end lines aimed specifically at adult fans with a focus on nostalgic brands.

"The definition of adulthood has definitely evolved," Chief Brand Officer at Jazwares toy company Jeremy Padawer said. "Now we feel a lot more free to express our fandom as a part of our adulthood."

According to Padawer, the start of this change in attitudes can be pinpointed to the '70s and '80s when harnessing intellectual properties became the dominant way to sell toys. With popular franchises like "Star Wars" taking off, toy companies turned to licensing to drive sales.

"At the time, the intended recipient was almost all kids," Padawer said. "But those children that were born in the '70s and '80s were really the first generation that had this much licensing and this much product that was available for them to demonstrably attached to. And it's not a big surprise, then that those kids is their 30s and 40s, that they continue to demonstrate that."

In addition to toys aimed at adults, toy companies have also started making movies specifically targeted at this demographic. Mattel (MAT  ) is set to release "Barbie" in 2023, and Hasbro's (HAS  ) "Dungeons & Dragons: Honor Among Thieves" will go to theaters in March.

However, taking advantage of nostalgia for franchises of the past isn't the only way companies are targeting kidults. Collector brands like Funko have always been aimed at both kids and adults, and other toymakers are embracing current adult interests in their products. For instance, Basic Fun, the maker of the classic toy Lite-Brite, partnered with Netflix (NFLX  ) to make a $100 "Stranger Things" version of its usual kids' toy. Even McDonald's (MCD  ) is getting in on the craze with its adult Happy Meal.

"We know that this generation does take their jobs very seriously, but at the end of the day, they also want to have fun," Razor's Senior Director of Marketing Josh Shave.

Razor first introduced its kick scooter in 2000, and the toy quickly became a staple of the decade. Recently, Razor introduced an "adult version" of its classic scooter for kidults: the $600 electric Razor Icon capable of reaching 18 miles per hour.

Along with trying to dig deeper into the kidult market, other toymakers are attempting to weather the inflation storm by introducing lower-dollar items. MGA Entertainment, the maker of the LOL Surprise doll line, is offering ten times the number of products below $15 compared to last year.

Still, these low-price items are meant to be a solution for cost-conscious parents, not a source for sales growth. On the other hand, kidults are willing to spend more for the toys they want.

"Right now, adult toy buyers are the reason for growth in the toy business," MGA Entertainment CEO Isaac Larian told CNBC.