Behold! Ultra Horror Series - The Revival of the Half-Fish Man (見よ! ウルトラ怪奇シリーズ・よみがえる半魚人 Miyo urutora kaiki shirīzu - yomigaeru hangyojin) is the nineteenth episode of Ultraman Leo. It is the third of the five episode story arc, Behold! Ultra Horror Series (見よ! ウルトラ怪奇シリーズ Miyo! Urutora kaiki shirīzu).
Gen and some friends go to Hokkaido, but the village doesn't allow fishing during the Bon festival. However, the Alien Boze may have been awakened.
Gen, Momoko, Tooru, and Tooru's sister go to Hokkaido. During the night, a man is fishing and pulls up a strange-looking kaijin. Terrified, he beats it to death with his fishing rod.
When they arrive on the island, they are told fishing is not allowed during the Bon festival. They say that this is because if you do, the sea monster will appear. Tooru says Gen is a MAC officer who could kill a monster. A boy asks Gen if he could kill a monster, but is chased off by a villager.
The boy runs off, and sees the body of Alien Boze. There is a flash of lightning and it revives. The boy runs off shouting for help. He goes to his parents, his father the fisherman from the night before. There is a lightning blast and he runs off, just before the fish monster breaks into the house and kills his parents.
Gen hears the child shouting for help. Everyone in the village hides. Gen attacks the kaijin and drives it off. MAC arrives, and obtains a picture of the monster's footprint from the local priest. Dan identifies it as an Alien Boze. It matches those the alien left in the sand, and MAC gets on patrol, but does not use the submarine because of the village's rules.
The boy cleans a rusty harpoon to kill the alien with. Meanwhile, several villagers try to sneak out in a boat, but are killed by Boze. Their screams alert MAC and the child, who throws his harpoon, wounding the creature. MAC drives it off, but it escapes into the ocean. Dan orders the rest of the MAC officers to get the villagers to safety, and orders him to stay behind because the alien would return a giant.
Dan takes Gen to another place and randomly begins to whip him. He tells Gen to try whipping him, and when he does wraps it around himself, regaining control of the whip. They are interrupted when the alien arrives. Mac attacks, but is no match for the monster. Gen transforms. He knocks off its whip and it dies in a billow of smoke and skeleton.
Gen, Momoko, Tooru, and Tooru's Sister say goodbye. The Boy is adopted by one of the villagers who lost his wife. End.
- Ultraman Leo Volume 5 features episodes 17-20.