Name: Naku

Gender: male

Species: Dog

Breed: Siberian Husky

Parents: unknown

Siblings: unknown

Mate: Ainu

Children: Balto, Nyack

Other Relatives: Aleu, Miryu, Jen, Shelley (granddaughters); Dingo, Saba, Kodi (grandsons); Jenette (Jenna's mother); Jenna (daughter-in-law)

Occupation: sled dog

Features: thick husky fur, husky markings; has the same markings as Jen

Colors: greyish brown and tan

Naku is Balto's husky father.  Contrary to what Balto believed for so many years, Naku never died. 
Naku was a part of a sled team that traveled often.  During one of his trips to Nome, Naku met and fell in love with a wolf named Ainu.  Naku visited his family in the wild as often as he could, but one day his humans took him away from Nome, and therefore his family. 
Naku wasn't able to return to Nome for years after that.  When he returned to Nome, he had no intension to search for his family, for he knew Ainu had died and had assumed his pups had died with her.

Jenna was the first to spot Naku's physical similiarities to Balto and point out that they might be related.  Balto immediately shurgged off the idea.  A few days later, Balto confronted Naku, simply saying hello, and somehow the conversation turned towards Naku's history, in which he said he missed his wife, Ainu.  Balto then told Naku he that he was his son, but Naku thought he was playing a sick joke on him.

Later, Balto asked Naku to meet him at his boat, to prove that he was his son.  Balto and Jenna present two of their pups--Jen and Shelley; Jen has the exact same markings as Naku and Shelley greatly resembles her father and paternal grandmother.  Naku is convinced afterwards that Balto is his son.

Having met Balto, and glad to know he's living happily with a family, Naku is able to leave the next day with his team.

Is it unsure whether or not Naku ever met his daughter, Nyack.