Number 65 normally appears as a light blue, ghost-like creature with a long tail/extension cord coming from his base and running normally somewhere off-screen. The number 65 is tattooed on his forehead, his eyes have a crosshair-like appearance, like the sight on a rifle, and an 'X'-shaped patch is taped across what is revealed to be a small mouth with sharp teeth.
Number 65 is the 65th model of a series of robots designed by the science section.
Number 65 is first seen when Allen Walker finally reaches the European Branch of the Black Order, where he seems to be controlling the golems that act as the building's security cameras. When the Gatekeeper comes to the misguided conclusion that Allen is an Akuma, Reever Wenhamm makes to order Number 65 to alert the other Exorcists in the building when Number 65 assures him that there is nothing to worry about, as Yu Kanda is already on the scene. When Allen explains that his teacher, General Cross Marian should have sent a letter of recommendation to Komui Lee, Number 65 is one of the many who look at Komui expectantly, and Komui, to the exasperation of many, reveals he probably lost it on his messy desk.
Number 65 was made in such a way that he could not leave the Former Headquarters. As a consequence he had to be left behind.
- Number 65 spends his time wandering around the European Branch, likes children, and dislikes Komlin II. He needs a blanket. 
- Besides Number 65, other smaller ghost-like creatures are seen wandering in the Science section. It is unknown if they are independant or dependant of 65.