Tig

Tig, being a familiar with that of Hyrah Runestedt means his primary role as a working animal means he acts as a conductor and loosely speaking, a sponge for the magical energy Hyrah uses in her daily life as to not overload herself with casting essence as well as a guide to help her direct said magical energy as she casts it, essentially acting as a secondary wand, but with the benefit of doubling as a spiritual guide and companion. 

Tig, like others of his kind, is bred and hatched especially for the task of aiding casters in whatever discipline they inhabit. The caster themselves are in charge of developing the egg with ritualistic care for a said period as though they were raising any other animal from egg to chick. Once hatched an unbreakable bond is formed between the two, which typically lasts for life. If a caster dies, so will the familiar. If a familiar dies, the caster will not, however it will mean forming another bond and raising another familiar will prove difficult. Because of the importance of these creatures and their roles the familiar is fiercely loyal and often snappy to others and hardly leaves the side of the caster.

They are very high maintenance animals in that they need a specialised diet consisting of vegetation of magical properties to support them, alongside standard meat or fish diet. They will, however, eat anything and everything without discipline so this is a factor to consider for young casters. 

Their outward appearances differ on regional factors and needs of the caster, as well as how the caster chooses to incubate their young familiar whilst it's an egg, but they share a quadrupedal stance, horns, opposable thumbs, and various amounts of plumage of tufts of fur on their bodies accompanied by scales. Rarer more elaborate breeds may possess wings or two fails but this is a very expensive result requiring rigorous attention to the young during incubation and is usually only reserved for the rich or very experienced.

Familiar temperament varies on the tamer’s training but it's a standard for them to be snooty, mischievous and territorial as a default. 

Trivia:

Tig and familiars in my world in a general sense are inspired by the mythos of wolpertingers physiology wise. Tig shares inspiration with those of Alebrijeswhen taken into account of Hyrah’s Mexican inspirations. Other inspirations consist of the terrible terrors from How To Train Your Dragon, racoons and tanukis.

Troren and Tig, to Hyrah’s obvious displeasure, have a war of their own when he's home from the front.

Tig, despite Hyrah and her stellar care, is a tad chunkier than most familiars on account of routinely stealing food from neighbours or farm animals.

Just like how caster’s tattoos, eyes and markings glow when they cast, so do the markings and eyes of Tig.

>Headcanon voice<