TV-Series
Description
Hyena, a Weimaraner dog, displays light gray or white fur in the manga, while the anime gives him darker gray fur, a white muzzle, brown eyes, and a red collar. His early personality is marked by extreme timidity and cowardice, rooted in abandonment by a former owner that bred deep distrust of humans. He acts as a minion to Dobermann Sniper out of fear, spying on Riki's pack. Though disliked by many pack members, Ben's insistence secures his acceptance despite occasional disrespect. Hyena exhibits cunning and effective lying unless panic overcomes him; he is a poor fighter and only engages in combat with strong allies like Sniper nearby. He obeys Sniper's kill commands.

His loyalty to Sniper wanes as he recognizes Sniper's disregard for his safety, frequently sending him into peril. This disillusionment drives him to seek friendship with John, who rejects him. Gradually, Hyena shifts allegiance to the pack, demonstrating newfound loyalty, joining battles, and showing concern for others. He develops a fierce hatred for traitors, exemplified when he attacks Terry under false suspicion of betrayal, later apologizing. His courage grows, enabling him to confront bears and eventually face Sniper, though residual fear lingers. A notable trait is his preoccupation with food, such as eating honey before battle to avoid dying hungry.

In "Ginga: Nagareboshi Gin," Hyena witnesses Sniper attack Ben at a cliff during the final battle against Akakabuto. After Ben throws himself and Sniper off the cliff, Hyena mourns Ben but hears his howl, signaling survival. Overcoming fear, he jumps into the river to rescue Ben and attacks Sniper in the water to free him. The anime adaptation alters this: Hyena leaps off the cliff in despair, committing suicide believing Ben dead.

"Ginga Densetsu Weed" reveals via flashback that Hyena survived the river fall, pulled Ben to safety, and confronted Sniper. He renounces allegiance to Sniper, declaring his changed character. Acknowledging he cannot defeat Sniper in combat, he sacrifices himself by pushing both into the river, where Sniper slashes his stomach underwater, killing him. Hyena later appears as a spirit, welcoming deceased characters like Moss into the afterlife.

"Ginga Densetsu Noah" retcons Hyena's fate: he survived the river by clinging to a tree and was rescued by a human. Suffering amnesia, he was renamed Noah and lived with his new owner until the owner's suicide via car crash. Noah survived and began caring for lost puppies with allies Buna and Kogomi. He encounters Orion, Gin's grandson, triggering fragmented memories of his past. Later, Shou, a Tibetan Mastiff commander of the Aka-Ari army, attacks him, crushing his skull. This blinds him but grants heightened sensory perception. The trauma, combined with visions of spirits like Ben and John, restores his memories as Hyena. He aids Orion by predicting a meteor strike and advising dog unity for survival. After helping defeat the Aka-Ari brothers with Sirius, his body washes ashore, deceased but with a peaceful expression.