A pregnant Princess Elsa staggers up the stairs clutching her stomach. Disney’s popular heroine pauses, and with a loud fart, poops out a stream of colored plastic balls that bounce down the stairwell. The video, posted to YouTube, has collected millions of views. In another video on the same channel Joker gets into a serious makeout session with Rapunzel, which is odd, but less bizarre than the clip where Spider-Man impregnates the evil queen Maleficent.

These surreal scenes sound like something that would bubble up in your subconscious, but they are actually meant as children’s entertainment. In fact, they are some of the most popular videos on YouTube these days. Adults dressing up in costume and acting out weird, wordless skits has become a booming industry on the world’s biggest video platform. The fourth most popular channel in the US in recents weeks, with over 100 million views, is dedicated to these homemade superhero soap operas.

What’s driving this madness? There have been two changes to YouTube’s audience over the last few years. The proliferation of smartphones in areas where internet access was previously rare has made YouTube far more international. 80 percent of YouTube views now come from outside the US. Videos that aren’t in any specific language, like most of the Superhero skits, can therefore reach the largest audience.

“Young kids' viewing patterns are a lucrative opportunity.”

Second, a massive number of very young children began watching, driven by the arrival of a kid-friendly YouTube app and parents who are increasingly comfortable sharing their smartphone or tablet. YouTube Kids has been downloaded by tens of millions of users, and collected over 30 billion views during since it debuted.

The result has been a gold rush around kid’s videos. Toy unboxing videos now account for about 20 percent of the top 100 channels on YouTube worldwide. And the most popular YouTube channel in the US for the last five months and counting has been Ryan’s Toy Reviews, which consists of little more than a five-year-old opening toys and playing with them.

Easy to replicate, cheap to produce

Superhero videos, like toy videos, are proliferating because of the massive audience and the low production costs. All you need to get in the game is a few Halloween costumes and some spare time. “These video are incredibly replicable, anyone can do it, which is why it spread so wide and so fast,” says Josh Cohen, co-founder of Tubefilter, which covers the online video industry, and was the first to cover this bizarre trend. “It’s tapping into the same theme as the toys. The little kids are already familiar with these characters through consumerism. If they have been to a Walmart or worn diapers in their two or three short years of life, they probably see these characters every day.”

Young kids have different viewing patterns than adults, and that is creating a lucrative opportunity. “From what I’ve seen, the reason they are getting these massive views is because kids, especially very young kids, have a tendency to want to watch one thing over and over,” says Phil Ranta, who represents one of the top superhero channels, Webs & Tiaras. “Some of these are probably seen by the same child 50 times. It really helps to juice those numbers.”

Aimed at kids as young as two

It’s impossible to know the exact age of the audience, because YouTube doesn’t allow anyone under the age of 13 to create an account, and most kids are watching on their parent’s account. Based on demographic research, Ranta estimates that “two years old to eight years old is where its hitting really hard.”

Most of the content on these superhero channels is puerile but benign, however the booming popularity of the genre has also attracted some notorious YouTubers who are piggybacking on the trend with videos that veer into violent or sexual situations which aren’t appropriate for young kids.

Kids using the normal version of YouTube, as opposed to the YouTube Kids app, are always at risk of stumbling upon strange material. “You’re watching a vlogger, and after three or four clicks, you wind up on someone else who is using worse language or talking about racy topics,” says Cohen. But typically those channels aren’t appealing to children, and certainly “are not putting on a veneer that would be really appealing to kids. Some of the more risqué types of programming in this genre, they are candy coated for kids. That’s what makes this more concerning.”

Risqué material candy coated for kids

“I think it’s natural that when something is as big as this [new genre] is, and they see people making millions of dollars a year, they will try almost everything: go cleaner, adding dialog, go sexier, or crazier,” says Ranta. So far, the lewd approach hasn’t been attracting nearly as many views. “They kind of just need to exhaust those measures before they realize if they can stay in this game.”

Poop jokes pull in the views

Ranta is certainly right about the rapid evolution of the genre. Channels are experimenting with Claymation, zany challenge episodes, and pranks, trying to weave together popular YouTube tricks to supercharge the views they can get out of their knockoff superhero adventures. And yet, despite the hundreds of channels and thousands of videos produced each week, they all seem to cue back into a few key themes.

Peeing, pooping, kissing, pregnancy, and the terrifying notion of going to the doctor and getting a shot. These are the Freudian concerns which young children find endlessly fascinating, frightening, and hilarious. The fact that a video of Spider-Man peeing on Elsa while she sits in the bathtub is insanely popular may seem bizarre — unless, that is, you have kids of your own.