My coming work features the Revkavir, monsters that are formed off lingering memories. They have a myriad of forms and I designed most to be an amalgam of mythological and occult creatures with a touch of eldritch horror. More powerful Revkavir form from more pervasive and shared memories, however I guess I can't spoil the stronger ones. ;p
A lesser one would be the Eyeshock, a roughly humanoid creature with multiple, mutated limbs and a odd skin tone/pattern. Not too threatening though? However the idea of the Eyeshock is that's appearance and skin pattern triggers a mental shock in the human brain, inducing temporary blindness. It's idea is based on the concept of averting one's gaze from horror and the myriad of optical illusion pictures out there that play on the human brain. Besides that, they usually don't come alone either.