Once the Familiar of a Witch, Pyrrhus was a faithful companion until the very end of her life. His Witch had been a healer, she' use her powers in aid of children in a village near their home in the woods. There weren't many who would speak badly of her or report her to the Royals, she was considered as the Village's Guardian Angel. Of course, tragedy strikes where you least expect it. It was and outsider who caught her in the act of healing a child one day. He drew the attention of The King's Men, soon enough the village was burned to the ground for housing a Witch, their cabin in the woods was soon to be the next target.
Neither she nor Pyrrhus knew any sort of magic to defend themselves, the most they could do was delay the inevitable.
Pyrrhus was found in the shape of a beast, growling but never attacking the men who had turned his life upside down. The last order from his Partner had been to survive this raid, no matter the means. He was captured and taken to the castle, intended to be used to search for more Witches. Were he truly an animal and not a shapeshifter, it might just have worked. Unknown to the men of the castle they'd brought back a very wise, and very angry creature.
While he remains a quiet and obedient creature during the day, Pyrrhus takes his true form at night. He tries anything to earn favor in the castle, working his way up to the very top.
Pyrrhus wants to avenge his Witch, and every person in his village who lost their lives for no reason.