Harpooned Bear is a monstrous brown bear from Hokkaido, known of killing a total of 34 humans.
Ginga Nagareboshi Gin
When a ship from Aomori was moving close to Hokkaido's shore, the bear swam in and ate the crew. The bear survived 3 months by eating the meat of 25 men.
The men fought back and launched three harpoons into the bear's back but however it didn't make him flinch in pain and the men were killed afterwards.
The ship eventually returned into Aomori but it seemed empty. 5 of local public officers went in and soon got attacked and killed by the bear right after discovering bones of the deceased crew.
The harpooned bear jumped out of the ship and scared the relatives waiting outside for their lost loved ones. The bear killed 4 of them while running away.
Year from this, the harpooned bear moves to Ohu, possibly after hearing news of Akakabuto. He easily kills Akakabuto's highest lieutenant, Kesagake and meets the Ohu dogs. They've tried to fight him but he had seemingly steel hard muscles due to swimming for many kilometers and then several dogs died in the process. He was about to kill Gin with one swipe but had his own agenda and it is that he leads the dogs into Akakabuto's fort and plans to defeat the big bear in order to take over but quickly changes his mind after seeing how big the other bear is. In fear, the harpooned bear wishes to join Akakabuto's forces but Akakabuto refuses and kills the infamous bear with one blow.