Most of you are likely familiar with the
SCP foundation, which grew from
this legendary one-off creepypasta into an entire massive continuity wherein a secret agency collects and contains things that threaten the safety and sanity of mankind, ranging from harmless but unexplainable oddities to mind-bending doomsday horrors. One of its key gimmicks is that we're only seeing snippets of leaked information, with a lot of the more disturbing and serious details left to our imagination.
They vary in quality, of course. Personally I dislike the overly religious/supernatural/mythological SCP's and prefer they be more original and vague than that, though some of those are still written pretty cool and creepy.
Some of my personal favorites:
The severed human head that thinks it's a crabThe animated fossil seabed.The flesh that hates - one of the really epic ones. Read the "field logs" at the bottom for a great piece of horror fiction.
The giant "coral" monster - this is a rather special one, designed to give readers an idea of the horrifying secrets the foundation hides from the public. The entry itself just describes a rather unremarkable reef-like sea monster, but the report at the end and the two links below it disclose a full report revealing a
lot more to the thing, and if you're into the kind of stuff I design for Mortasheen and write about for Bogleech, it might end up your favorite thing on the site.
The Architect - an object which somehow adds expansions to any structure it's contained in without changing the outside, and never ever stops. The longer it's allowed to do so, the more
wrong things go...and once again, you can find out more from the log linked at the end. It's delightfully creepy.
The cancer garden - implying a sinister secret behind cancer itself. You know, more sinister than just cancer.