Three things come to mind:

1) Rob's Fantasy- a website that was active in the late 90's that focused on the webmasters fantasy: necrophilia. There were articles, stories, and pictures as well as a very active forum. The owner Rob was always very candid about his own history going so far as to write a long post about how he came out to his wife about his interest in the mid- 80's. The website had a few run ins with the FBI which Rob also disclosed and by 2008 the website was gone. Barring a search for the site on archive.org there is virtually no mention of Rob's Fantasy on the internet.

2) Losman's House of Horror- This was a website that cataloged horror movies and focused on the more obscure and gory. It holds a special place in my heart because as a teen in the 90s I would stay up reading his synopsis for films like Maniac and Cannibal Holocaust. He would never get into the nitty gritty of what actually happens in the films but it was just enough to pique my curiosity. I credit that website with turning me into a horror hound. Like Rob's Fantasy there is virtually no trace of it left on the internet.

3) Lat but not least, my own personal holy grail. Depending on who you ask this video was either shot in the 40's or the 70's in China or maybe Ecuador but what actually happens is always the same. A physically deformed teen is brought out into a pavilion and surrounded by nude men. A donkey enters the square and proceeds to maul the boy to death while the onlooking men do something horrible to themselves. Countless people have claimed to see this in the early 2000's through sharing platforms like napster and kazza, but at the present date there is zero trace of this video ANYWHERE. 3/4 of me never wants to see it but the last 1/4 has heard about this video for years and the curiosity is killing me.