Archie

The Librarian is a character that appeared in the episode The Last Laserdisc Player. He was first seen in the Library and was willing to help Mordecai, Rigby, Muscle Man, and High Five Ghost get the laserdisc player to play their movie. The Librarian revealed that he was supposed to watch over the last laserdisc player after the Ancient Order of the VHS destroyed the rest of them. After activating the Guardians of Obsolete Formats and retrevie the laserdisc player, SP and  along with the rest of the Ancient Order of the VHS suddenly appear and begin attacking the group. The Librarian was eventually hit and asked Rigby to place the tape on him. The Librarian soon transformed into the Laserdisc Guardian and wiped out the Ancient Order of the VHS.

Appearance
The Librarian is a tall human that has grey/brown hair and a mustache. He also wears glasses and a suit. In his Laserdisc Guardian form, he appears as a giant, golden crystal-like monster.