The so-called "Momo Challenge" has become something of a nightmare for parents.

"It's horrific," Susanne Buck, a Kings Park mother of three, says of the challenge.

While the challenge has become a hot topic this week, Buck says her children started finding terrifying videos on YouTube two years ago.

"It progressively just got into worse videos," she says.

Instead of just showing kids creepy content, the challenge is even encouraging them to do things like harm themselves. Those videos convince kids that if they don't listen to the cartoon in the video, Momo will curse them.

Buck's sister, Jennifer Cuevas, is a social worker who says kids seeing the videos are often dealing with anxiety and depression, making them susceptible. Cuevas says that while videos like these aren't anything new, she does believe that whoever came up with the Momo Challenge exhibits sociopath tendencies.

Some local school districts have sent warnings home to parents about the videos.

YouTube says it sees no recent evidence of videos promoting the Momo Challenge on its website.