What is the creepiest unexplained thing you have ever come across on the internet?

A video of someone taking a doll apart and putting the bits into a pan of boiling water. It was shot in black and white and s'posed to be from the dark web.  

There are channels that can make all hair stand on end. I did came across few while surfing web aimlessly few years back. Those sites disappear or blocked often. You see them, they can see you!

They don't allow creepy stuff on the internet so nothing really...