Odin, the Northern Inuit Dog who played the direwolf "Summer" on HBO's Game of Thrones, has passed away after a four-month battle with cancer.

He was owned by a family in Northern Ireland and lived to be ten years old, according to BelfastLive. As a widely recognized and loved pet, he had many donations offered for his vet treatments from the public, but his illness continued to progress and he passed away in his sleep on Wednesday.

RELATED: Sophie Turner Reveals What She Misses Most About Game of Thrones

In the first episode of Game of Thrones, the Stark family rescues a litter of newborn direwolf pups which play significant parts in the lives of the characters as the story expands. Bran Stark's pup, later to be named Summer, is seen watching him climb the walls of Winterfell in the same episode.

The direwolf is a fictional species inspired by the prehistoric dire wolf, and according to the mythology established in George R.R. Martin's books, they can grow to the size of ponies. As the pups in the series aged, their canine actors were replaced in large part by CGI effects.

Northern Inuit Dogs are a breed with a wolfish appearance that looked just right for the direwolf pups early in the series. Along with Odin, another Northern Inuit was used on the show to portray Sansa Stark's pup, and was later adopted by Sansa's actor Sophie Turner.

RELATED: Game of Thrones Actor Disagrees With You, Calls Series' Ending Perfect

Odin's owners said that he was “a family member first and we got him when he was a pup at seven weeks old.... Odin’s passing marks the end of a decade and the end of an era as he taught our friends and family a lot of lessons about life for one dog he has more stories to tell than some people would."

Game of Thrones stars Peter Dinklage, Nikolaj Coster-Waldau, Lena Headey, Emilia Clarke, Sophie Turner, Maisie Williams and Kit Harington.