Kowethes

"Kowethes!" A familiar voice hollers "Kowethes!"
She opens an eye to look up from her wicker dog bed at Duncan. He has been her stalwart companion for over 2 millennia now, and always did his best to keep a roof over their head and food on their plates, and all those other things humans like to do. Although such offerings were expected for someone of her stature, she did her best to repay him by making sure he didn't get in to too much trouble.
"Kowethes, there is a parcel I need to collect from the post office. Whilst I am away, I need you to guard the shop, make sure no one comes in, and make sure nothing comes out of the basement. We know what happened last time."
Kowethes groans and closes her eyes.
"Oh, don't give me that, I know full what you did." Duncan says as he heads to the door "It took days to clean up that mess."
The door latch clicks shut behind him as he leaves, and Koweth's eye flicks open again, and in a moment, she bounds across the room and on to the couch, pawing at a TV remote until loud music fills the room. She hops back down, and trots to a tall set of shelves, where a box of dog biscuits sits high out of reach.
Koweth barks and paws at the air in front of her feebly. Her paw extends, and with it her entire body, until standing in her place is a lithe, blonde woman, who snatches the box a grin, fills a bowl by the wicker bed, and tosses the empty box over her shoulder.
The lithe woman sits on her haunches in the bed, and with a *phooph*, Koweth's canine form takes her place, curls up, and closes her eyes.

Kowethes isn't her real name, her real name hasn't been used for countless generations, it may even be forgotten, but one thing is for sure, Kowethes certainly isn't telling anyone, even if she could.
Names have power
You see, Kowethes is a fairy.
No, not the butterfly winged, sparkly pixie fairies of children's stories. Something far older and more powerful, the hidden folk, the people of the mounds, a púca, the elfin demi-gods clad in bronze armour of ancient Western and Central Europe. To believe their detractors, they are tricksters, child snatchers, flesh eaters and demons. While there may be an ounce of truth to some of this, just as humans are a multifaceted and varied bunch with both noble and evil individuals, so too are they.
Kowethes did once favour her humanoid form, millennia ago, during the time described in Lebor Gabála Érenn. While the Tuatha Dé Danann walked the earth, she served as a simple handmaid to Ogma, the god of language and eloquence. When the half-Formorian Bres was made king of the Tuatha De, and his subjugation of Nuada's court began, Kowethes spoke harshly of him and the treatment of her master. In retaliation, Bres ordered her tongue cut from her mouth, attached to a silver chain and presented to her master, who was often depicted as leading his followers by silver chains by his tongue. The act was orchestrated as a direct insult towards Ogma
This wasn't just an insult, however, as for the Aos Si the figurative and literal sometimes blur, and the loss of her tongue meant the complete loss of her voice, even if she used her ability to change form to grant her a new tongue, or if she were to attempt to write.
With one exception.
As animals do not speak, she found that while in various forms, she was still able to vocalise. A bleat, crow, or bark provided some relief from the continued silence whenever she opened her mouth.
And so began her habit of remaining in animal forms, her preferred being that of a full-tailed Cardigan Corgi.

To outsiders, Kowethes may appear to be a very intelligent dog, and she has been referred to as Duncan's "Animal Sidekick" on multiple occasion. In actuality, she is the stronger, wiser and older of the two, in her mind, Duncan works for her. His occasional chastisement and insistence that he is in charge is at best amusing.
Duncan is aware of Kowethes' nature as a Aos Si, but knows nothing of her deeper past, having met her long after the loss of her tongue. His knowledge of her kind inclines him towards playing along with her choice of form, lest she becomes insulted.
Kowethes sees Duncan as a source of entertainment, he seems to find trouble easily, and his inability to stay dead makes him a curiosity. While she takes enjoyment from keeping him out of trouble, she is not beyond leading him in to it herself just to see what happens. The fact he doesn't suffer any permanent harm keeps her conscious clear.

Like many fae, Kowethes may appear to be amoral, self serving, vindictive and a prankster. In truth, she adheres to a code of conduct and honour alien to our culture, and with a different idea of right and wrong. She finds remaining in her canine form helps this greatly, as people seem far more forgiving of a dog when she chooses to steal or break something.
Kowethes is spirited and adventurous, but also ultimately quite lazy, content to while away the day sleeping in the sun, or wasting away hours on some pointless activity. The life of a dog suits her down to the ground, even if it she is a magical dog who is more than capable of convincing a tree to shake a squirrel loose after she has chased it up there.
The meat flavoured crackers people seem to enjoy offering her aren't too bad either.

The Corgi is a herding dog, and Kowethes is rather adapt at herding, at least through means of magic rather than traditional heeling.
However what she chooses to herd tends to be large and somewhat dangerous animals, rather than cattle. She believes they are far more useful.
Her current "herd" includes four wolves she has named MacCuill, MacCecht, MacGréine, and Dagda, after the last kings of the Tuatha De and the god of magic; two large cougars, called Taltiu and Ethniu, after the mother and foster mother of Lugh Lámfada; and a group of crows, which she calls squawky flappy bird flock.
This magical coercion isn't just limited to animals, as she is also able to influence flora, increase its rate of growth and mobility.
Kowethes is also capable of shapeshifting, and is adept in various forms of mending and healing magic.
She once almost nearly caught her own tail without cheating, and can balance small objects on her nose. At least in canine form.