I'm sorry, friend, but if you're looking to learn something new today, that something doesn't exist. Yes, I understand perfectly: once you start learning the unsettling secrets of the Foundation, the urge to dig deeper is strong, but I'm afraid this time you'll end up disappointed. No matter what you've read or heard, that hypothetical interdimensional creature that allegedly steals any bit of information related to its being doesn't exist in reality.
Moreover, I'm sure you already have the same information I do. The texts tell you to imagine a strange, humanoid creature more than two meters tall. It is completely black and passes through solid matter easily, a trait that would make its containment impossible (if it existed in the first place, of course). Another typical detail is that it has a set of sticky tentacles instead of hands. Nothing it captures with those tentacles is supposed to escape, but no one can know for sure because that creature doesn't exist.
Now, this is the most interesting part of the fantasy: this... bug that magically crosses walls and doors seems to suffer a kind of obsession with anyone who tries to identify it. It doesn't matter if the information is written on a piece of paper, stored electronically, or said aloud; that's enough to attract its attention. What does it do? Well, in theory it wraps the "source" with its tentacles, presses it against its body, and takes it away... who knows where.
Some say it devours what it takes. Others think it's like... narcissism? In love with itself or with the one who mentions it? I think it would be the first in the Foundation, if only it existed. That's how things are. I don't even have a name to share with you. Something tells me it's the invention of an online blog looking to make some noise and scare kids. Don't worry, your hands will end up fuller next time... if that's what you want. Desires are dangerous in the Foundation, I imagine you already understood that....
DON'T LOOK DON'T ASK DON'T SPEAK DON'T INSIST DON'T NAME HIM DON'T THINK OF HIM HE WILL KILL YOU DON'T LOOK DON'T ASK DON'T SPEAK DON'T INSIST DON'T NAME HIM DON'T THINK OF HIM HE WILL KILL YOU DON'T LOOK DON'T ASK DON'T SPEAK DON'T INSIST DON'T NAME HIM DON'T THINK OF HIM HE WILL KILL YOU DON'T LOOK DON'T ASK DON'T SPEAK DON'T INSIST DON'T NAME HIM DON'T THINK OF HIM HE WILL KILL YOU DON'T LOOK DON'T ASK DON'T SPEAK DON'T INSIST DON'T NAME HIM DON'T THINK OF HIM HE WILL KILL YOU SCP2521ERROR