Montresor

Montresor(モントレソール; Montoresōru) is a very intelligent snake spirit and the Familiar of Ichijou Tsukino in Volume 11 of the Highschool DxD: Яe-birth continuity.

Appearance
Being a snake spirit, Montresor is a rather long, scary-looking viper of around 12-meters length of golden blinkless eyes of slitted eye pupils in a constant frown, dark-coloured scales and parted tongue, which usually ticks out for intimidation. His most unique trait, however, seems to be the crown-shaped crowning on top of its head, which made others believe he was in fact a basillisk.

When it needs to disguise itself, however, Montresor takes the form of a small, overweighted and rather adorable ribbon snake of lighter tones and fangless.

Personality
Unlike other familiars, Montresor seems to be highly intelligent and self-aware, enough to distinguish time and the period of Full Moon, the time where devils would enter the familiar forest. Although mute, he also has a rather dry sense of humour, mocking his to-be master with pranks and suggestive body movements, only to intensify them when getting a reaction out of him. It's also intelligent enough to be arrogant and greedy, considering himself to be a superior familiar, while also showing ambition to cling onto Ichijou, the Red Dragon Emperor, out of fun, profit and pride.

After becoming Ichijou's familiar, however, he develops a developing respect for his new master, and while refusing to consider himself his, Montresor likes to stick around Ichijou to see him do more 'interesting actions', alwhile making fun of his constant missadventures. He also grows fond of his name Monstresor, and only responds for anyone's calls if called as such.

History
Not much is known about Montresor's past since he's a snake spirit, therefore a manifestation of nature taking physical form. In some time in the past, the until-then nameless spirit found his place into the Familiar Forest and using his high intellect to study both the native creatures and devils that would walk into the forest looking for a familiar. For the longest, the spirit would wander and play around the forest and its inhabitants, until finally be converted into an familiar, seem the unusual aura around his devil, Ichijou Tsukino.

Powers & Abilities
High Intellect - Unlike other familiars, Montresor possesses a level of intelligent at least on par or even superior to those of other devils, as he could determinate time and moon periods one would go into the Familiar Forest, as well as having a sense of self-awareness, being able to even wordlessly comunicate with other species. However, Montresor has limited knowledge about anything else but the Familiar Forest. Stealth - Being a snake spirit, Montresor can easily cease his presence and aura from others, blending into the enviroument with rather ease and being to pass undetected by devils, humans and other familiars, also being able to hide into Ichijou's clothes during school periods without being seen. He also possesses high stealth skills, which Annabelle says it's akin to a high-class ninja.

Fangs - Being a snake spirit, Montresor possesses fangs which excrets a venom which despite being harmless to devil, humans and angels, are able to make its victims feel a 'shiver' sensation.

King's Will - A rather unique skill that Montresor developed living with other bigger familiars, he's able to manifest a powerful, intimidating aura which makes those of weak heart 'step down'. Unlike conventional Killing Intent, Montresor instead projects an aura of both fear and respect onto his victims, and either by those two factors, make them cease their assault, described as a 'resolution of one true King'.

Trivia

 * Montresor's appearance and images from the snake king from the Queen of the Beast manga.
 * Despite, or rather because, being a snake spirit, Montresor doesn't need food to live. However, he eats out of pleasure. His favorite dish is grape juice and fillet mignon.
 * Montresor doesn't talk, but Ichijou apparently can hear his voice. If its any form of mental link between the two or Ichijou projecting some thoughts into his familiar it's unknown.
 * Snakes are usually considered proto-dragons in some lores, mainly eastern ones(see Imugi). Montresor is, above all else, a manifestation of Ichijou's position as Issei's foil and successor.