Pip Squeak

In Curse Of Strahd, Pip unknowingly became a member of the Pack, as Ghalwin ventured to the lands of Barovia. Despite the dangers of this land, Ghalwin protected Pip from harm as tragedy befell most of his companions at various points; tucked in Ghalwin's plate armor, he would only leave if his "home" was flooded in water or otherwise compromised.

This pattern of Pip's life continued until a blind Ghalwin opened up to the land, and was granted gifts from the Ladies Three. Awash in a moment of singular magical attunement, Pip was granted sentience. Still cowardly, somewhat selfish, fond of burrowing, and hiding, Pip nonetheless proved invaluable to Ghalwin, who he began calling "boss". When not accompanied by Verity, Pip would act as Ghalwin's "eyes," informing the paladin about notable things in his surroundings. 

Pip did not quite understand his new form, as he lacked basic knowledge of the world but intuitively understood some concepts, which he referred to as "cursed knowledge". His ability to communicate in the common tongue was extremely off-putting to most Humans, and he quickly learned to not speak to strangers unless otherwise prompted.

As they traveled with the new group Heralds of Dawn, Pip was crafted a set of plate mail from the artificer Tobias Villie Broadnose Cogsmith, and bonded with Mormeros Fayan, who he considered to be a "vacation home." The mouse grew worried at his advanced age for his lifespan, and grew increasingly desperate for a mate before he turned a year old. Mormeros would torment Pip constantly about this desperation, however, including making a horrifying "mate" Familiar named Pop.