One part of the Slenderman collective mythos has been establishing a historical background. Backfilling Slendy's present video and digital photo presence with mock-archival images is the work of many hands, neatly assembled here.
Country of Origin: Japan
Similarities to Slender Man: faceless, tall, thin, deceptive, can appear differently
Freaky Backstory: Noppera-bō like to scare humans for fun. They can be male or female (like the one pictured) and take the form of a person known to their victim - before dissolving their features to leave a smooth, blank face.
But if we're going to use the "tall man" meme, let us please note this very great Tall Man.
It's fascinating to watch Slenderman, a native-born cyber Gothic meme, develop and expand.
(thanks to Geekymom!)