Please don't list this on a work's page as a trope. Examples can go on the work's YMMV tab.
Nightmare Fuel: Markiplier
An unintentional example but early on in his Youtube career, Markiplier would sometimes have problems, that his game would crash, fading back to the desktop. Apparently he likes to display some of the more infamous faces from SpongeBob SquarePants.
Recently, Markiplier has been endingsome of hisvideos in...very strange ways that need to be seen to be believed. "I've been having strange dreams lately..."
Lately whenever Mark plays a game that's in a 4:3 aspect ratio he moves the gameplay footage over to the side so the facecam doesn't cover the gameplay, but this leaves some major negative space on the left side of the videos. This troper has been freaked out one or two times now by the fact Mark takes advantage of said negative space to put creepy images in them that randomly appear and disappear via a slow fade, almost like faces looking at you in the darkness...
Mark's acting in bothparts of Cyndago's 'Danger than Fiction' videos are pretty disturbing. While having some funny moments, Mark is pretty dark in them, even threatening at that.
Some of the preview icons for his videos fall into this, as they tend to feature his face heavily photoshopped into either something resembling Body Horror, something straight out of the Uncanny Valley, or just plain creepy.