Britannica and her Familiar (Patreon)

A little bat.

As her familiar, the bat provides her with assistance during her periods  of voluntary blindness. Using echolocation and being magically  synchronised offers Briti an alternative way to see. 

On top of that, he eats any pests like insects or small rodents and birds. His favourite is moths. 

Briti is quite affectionate towards him. (As anyone should be with their familiars.) 

What kind of bat is he? I made it up, I just picked features of bats I like and threw them together.