Still Life (Backrooms) - All of the backrooms are like this, but the Still Life are the most. Basically, if I understand it correctly, everything in the backrooms is created from the collective memories of that thing. So if it would try to create a copy of, say, me, it would use memories of the people who know me to create the clone. The problem with memories is that they can get warped. The more you remember, the less you do, as they say. And the results are these messed-up-looking "people" with deformed features.
Agamemnon counterpart - An old creepy video from YouTube. It starts with text that says that, in the future, on a destroyed blue planet, someone found a cassette tape. It then proceeds to tell us that the video is completely different from what is on the cassette tape before showing us a messed-up and corrupted-looking cartoon. Now, it could all be random, made to confuse you; however, a popular theory is that the video is actually trying to tell a story. That in the future, when Earth is destroyed and humanity is seemingly extinct, an alien race finds a tape with an old children's cartoon and tries to recreate it. Key word being tried.
Empty Child (Doctor Who) - In World War II London, an alien spaceship containing Medical nanogenes crash-lands in London. Now the nanogenes' purpose is to heal anyone it deems injured. The problem with that is that, for it to do its job, it must know what the species it's trying to heal looks like and its biology. And it hasn't the faintest idea what humanity looks like. So when it crashed in London, it crashed right next to the corpse of a little boy who died during the Blitz. The boy was wearing a gas mask, and since the genes had no prior knowledge of humanity, it assumed every human looked like this, and those who didn't, it deemed "injured," so it started turning normal people into gas mask zombies, with the gas mask being a part of their face.
Old AI (Real life) - Now AI has become so advanced it can be really hard to distinguish it from real life, even with its flaws. But when it first came out, it... wasn't like that. It just mindlessly copied the pictures in the catalogue without knowing why or what it was trying to copy.