About:

I Am Now Going to Assault your mind with Subliminal Messages (or simply "Subliminal Messages") is a clip from the Season 2 episode of Spongebob Squarepants television show entitled "Gary Takes a Bath."

According to wikipedia:
…while SpongeBob is "assaulting Gary's mind with subliminal messages", a picture of a strange, crossed-eyed, awkward girl with freckles and pigtails appears suddenly with a disturbing giggle, and was deemed too frightening for younger viewers.

The offending picture in question

The scene itself was almost too perfect for parody and, despite the innocent and childish humor involved in most Spongebob episodes, became an outlet for almost disturbing video editing on YouTube.

Spread:

Fad apparently created by a YTPer named DrBlowJob before he was banned.

Like Youtube Poop, Subliminal Messages has a set structure in telling the joke: Spongebob opening, three previous subliminal messages, then the joke, followed by the apology. Though a few videos do occasionally spread off from the basic formula, the joke structure makes for a more sound, stable, and widespread fad than most YTP's.

[more to come]

Hypnotoad Version
https://www.youtube.com/watch?v=N5DUr66zzog
(Note: Embedding disabled by Request)