In Mesopotamian mythology Namtar was a hellish deity, god of death, and the messenger of An, Ereshkigal, and Nergal.
Namtar was considered responsible for diseases and pests. It was said that he commanded sixty diseases in the form of demons that could penetrate different parts of the human body; offerings to him were made to prevent those illnesses. It is thought that the Assyrians and Babylonians took this belief from the Sumerians after conquering them. To some they were the spirit of fate, and therefore of great importance. This being was regarded as the beloved son of Bêl. Apparently they executed the instructions given him concerning the fate of men, and could also have power over certain of the gods. In other writings they were regarded the personification of death, much like the modern concept of the Grim Reaper.
Namtaru is an F.O.E encountered outside the Cinema. It resembles a purple, levitating suit of armor with long sleeves, pointed legs, and a pair of golden and black wings on its back. It does not have free will and is just an extension of Enlil.
The Namtaru has a peculiar behaviour. While the party is in the same room as one, the Namtaru will mirror their movements - i.e. moving south when the party moves north, etc. Walls and low passages can hinder their movement and break the symmetry. Namtarus can float over empty spaces and their movements can be manipulated to hit switches that toggle the wind shields in the labyrinth. Once the party leaves the room, the Namtaru will immediately teleport back to its resting spot.
Defeating a Namtaru for the first time yields a Glutton's Mark, a key item that unlocks the special fusion for Beelzebub.