Twig is the pet and companion of Hilda, a blue-haired girl from the graphic novel and now Netflix series titled; Hilda.

Twig is a juvenile Deer-fox, one of the many wonderful creatures of Luke Pearson's world.
Deer-fox are a relatively unknown and illusive species with many people believing they are just made up creatures.

Twig met Hilda when he was just a a cub and has stayed with her ever since, even after being reunited with his family and given the chance to go to their hidden world in the sky, Twig decided to come back to Hilda and her mother as they have been his family for many years.