North is a loyal and trained dog. He respects Jerome a lot, but isn't sure about Weed's fighting skills, though he doesn't say this out loud. He explains things to the young pup and tells him that fear will kill you, just before getting killed himself.
North was one of the guard dogs that should make sure that the monster Kaibutsu didn't escape from a scientific institute. When the monster escapes anyway, North followed his leader Jerome to do everything they could to stop him. Jerome sets up a trap to trick Kaibutsu out of Gajō and North is to be the bait, along with Weed. North marches into Gajō, but is killed inside by Kaibutsu.
He is decapitated and in the manga, Kaibutsu throws North's head outside the fortress as a warning to the other dogs. In the anime, his whole body is thrown outside.