Zalgo/WMG

Zalgo is Yawgmoth.

 * Simple comparison:
 * Zalgo-ified image.
 * The Mask of Yawgmoth.
 * Any questions?
 * How did I not notice this sooner.

Zalgo is Amatsu Mika Boshi of Japanese Mythology

 * Amatsu Mika Boshi is said to be the dark essence of chaos from before creation and when the heavens and earth were born, it was shattered and now exists as fragments within all life and is a corrupting force from within. It also explains the Body Horror aspect, and makes it even worse when you realize WE'RE ALL ASPECTS OF ZALGO!

Zalgo is Giygas.
Think about it. Giygas makes people and animals act in an unnaturally violent manner. Plus, when you finally approach him, the player characters

Zalgo is The Slender Man.
Exactly what it says on the tin.

Alernatively again, Zalgo is Slender Man's underling.
I like it better this way.

Alternatively again again, Zalgo and Slender Man are bros.
This way is cuter.

Alernatively again again again Slender Man, the Rake, and Zalgo are all one big happy family.
This way it can be marketed as a terrible sitcom for Nick at Nite!
 * and Tanasinn can make guest appearances!

Zalgo inspired the KL-2 Entity from StarCraft: Frontline

 * Volume 4 of Starcraft: Frontline that features the KL-2 Entity was released in October 2009, half a tyear after the Zalgo meme was at the peek of it's popularity.
 * A dead star will sometimes be mentioned in Zalgo related text. KL-2 is a dead star.
 * Zalgo style corruption will usually target the eyes first. Victims possessed by the KL-2 Entity look like this.
 * ....OhCrap.

Missigno is an incarnation of Zalgo
Does this even need to be explained?

Zalgo is the source of Youngblood's Disease.
Zalgo's victims tend to lose their eyes, which is the result of Youngblood's Disease. Both affect comic characters.

Herobrine is a minion of Zalgo.
He has no eyes, and he is corrupting a seemingly-childish-and-innocent game.