It was Wuten's fault.
It all started on voice chat during the 194th thread, when Wuten said "you need me" in the voice chat, similar to the way Mr. Friendly says it in the YouTube video "you need me". After this, HeshieokFasla posted as an anonymous user onto the thread, "you need me", and it exploded into over 30 posts relating to something related to said saying.
The video, a 34-second video by JimboMcB on YouTube, is set in the Gmod game engine. The video consists of the player running away from a six-headed Gman, whose bones have been manipulated to have long necks and a distorted body. The creature, dubbed "Mr. Friendly" by most, follows the player unhindered, and every two seconds the heads all speak in-synchronous "you need me" in a distorted deep voice, while other heads make a "caw"-ing sound.
In Thread 200, Wuten and Chronicler posted "Mr. Friendly in Equestria - Chapter 1", which depicted an Anonymous who, through a series of unfortunate events, ended up face-to-face with the creature disguised as a pony. It ended abruptly when the Anon saw Derpy flying by, and asked for help. She replied in a similar manner to the first encounter the Anon had with Mr. Friendly.
This story is available on Wuten's Pastebin.