Ophiuchus

Ophiuchus is a powerful Celestial Spirit whose key type is currently unknown. Its Gate is referred to as the "13th Gate".

Appearance
Ophiucus' appearance is that of an humongous snake-like creature, which, curiously enough, appears to be part organic and part mechanical in nature. The upper part of its body is covered in a series of massive dark scales, which possess prominent holes on their sides, starting as larger, with squared outer edges, getting more narrow near their centers and then enlarging again, something which makes every single hole look like a pair of rhombs joined together; the upper part of the head and the corresponding jaw are similarly colored, with the reptile possessing light pupil-less eyes, a pair of massive fangs sprouting from the jaw, thin nostrils located on the front part of its nose and a series of dark motifs adorning its forehead, above the eyes.

The lower part of Ophiuchus' body, on the other hand, is visibly technological and inorganic: its upper scales, instead of meat, appear to house a vast number of metal panels lined up one near the other, something which makes them resemble closed blinds; its lower jaw, while seemingly topped by an organic tongue (which, unlike that of normal snakes, isn't forked, as well as being notably larger in comparison to the jaw itself than normal snakes') is entirely composed of metal, with the plates composing it, replicating the form of a real jaw, having their edges covered in lines of bolts. Such artificial-looking lower jaw is connected to the upper one by six piston-like objects, three sitting at each side of the creature's mouth, while a semicircular metal section covering the lower part of its neck, almost extending up to the top, sports two round openings on each side, with a single metallic bar outlining the diameter of each hole. The lower part of Ophiuchus' metal jaw sports a massive blade with jagged edges (which, however, is relatively small in comparison to the beast itself) curving toward the creature's body, secured to the front by a protrusion, and the attached for most of its length after an hollow space.

History
Not much is known about Ophiuchus' history, only that it made a contract with Yukino Aguria. According to Lucy, its power surpasses the 12 Gold Celestial Spirit Gate Keys.

X791 arc
During the Grand Magic Games, Ophiuchus was summoned by Yukino during her fight against Kagura Mikazuchi, but was easily defeated by the Mermaid Heel Mage.

Magic and Abilities
Immortality: As a Celestial Spirit, Ophiuchus cannot die, unless it is forced to stay in the Human World somehow.