I assure you it definitely does exist - a girl in my sons class was told to get scissors and cut herself - luckily she only cut her hair, which then meant the parents noticed and asked her what she was doing - its definitely out there
If you havent heard about this yet but have kids or grandkids - please spread the word - this is disgusting
https://www.mirror.co.uk/news/uk-news/momo-challenge-hacking-peppa-pig-14054996