Godzilla vs. Hedorah(1972)

Pooper:
Godzilla is able to power the machines that destroy Hedorah. After destroying his nemesis, Godzilla returns to the ocean as Ken and Miki wave goodbye to the victorious hero.

Long Ending:
A giant monster appears in the ocean around Japan, devouring trash and sludge that was dumped in the water and attacking oil tankers in order to drink the spilled oil. A scientist named Toru Yano (Akira Yamanouchi) scuba dives to collect samples of the monster, named Hedorah. He is attacked and injured by Hedorah, who has acidic skin. Although unable to work at full strength, Toru is able to conduct some experiments. He learns that Hedorah was born out of an alien substance (that likely arrived on Earth via comet or meteor) and feeds on pollution. The more pollution Hedorah eats, the more powerful it becomes

Toru’s young son Ken (Hiroyuki Kawase) develops a telepathic connection with Godzilla. At Ken’s urging, Godzilla comes to Japan where he finds Hedorah has evolved into an amphibious form and is ingesting exhaust emitted from factories. Godzilla fights Hedorah and largely manages to overpower the sludge monster. Hedorah manages to escape by oozing back into the ocean and swimming away. The fight is witnessed by Toru’s brother-in-law Yukio (Toshio Shiba) and his girlfriend Miki (Keiko Mari). They alert Toru who, along with his wife Toshie (Toshie Kimura) go to the site of the battle and collect more samples. Although Yukio and Miki postulate that Hedorah may actually be good for the Earth (since it eats pollution), Toru assures them that the Hedorah is a potential threat to the entire world.

Toru proves himself right a few days later. While at an amusement park, Yukio, Miki, and Ken are trapped in another battle between Hedorah and Godzilla. Hedorah has evolved once again, gaining the ability to fly. Hedorah flies by emitting a stream of acidic gas from its body. The gas knocks out Godzilla and peels the skin off of humans who are caught in its cloud. The main characters barely survive the attack. Toru pushes himself harder and is able to build a prototype machine that manages to extract all pollution and fluid from the samples of Hedorah he’s collected. He reports his findings to the Japanese Self Defense Forces, and they begin building the device big enough to destroy Hedorah itself. Meanwhile, feeling that humans are doomed either way (via destruction by Hedorah or by the pollution humans create that powers the monster), Yukio and Miki plan a party on Mt. Fuji to celebrate their last days on Earth. The pair bring Ken with them.

Through his telepathic connection, Ken senses Godzilla is nearby. He tries to warn the partygoers, but it is too late as the monsters converge upon Mt. Fuji. Hedorah has evolved once again, developing into a giant, sludge monster that is bigger than even Godzilla. Hedorah is able to shoot lasers out of its eyes, and its skin burns anything that touches it. Although both monsters injure each other, Hedorah soon gains the upper hand. Meanwhile, the Japanese Self Defense Forces manage to set up the full size device nearby. Toru and Toshie drive to the contraption to help operate it. However, the device is incapacitated when Godzilla and Hedorah’s battle knocks out the electricity lines powering it.

The partygoers try to interfere to aid Godzilla, but Hedorah kills most of them (including Yukio). Hedorah manages to knock out Godzilla and then buries the beast in toxic sludge. Hedorah then turns its attention to the Self Defence Forces. The military desperately tries to reconnect the electricity, but are unable to do so as Hedorah arrives. Just as all seems lost, Godzilla also arrives (having recovered and freed himself from the sludge) and shoots his atomic breath at the machine. This gives the machine enough power to activate, and it greatly injures Hedorah. The pollution monster attempts to fly away, but Godzilla himself flies through the air (propelling himself through the air with his atomic breath) and catches the wounded Hedorah. Godzilla drags Hedorah back to the device, and the device turns Hedorah into ash. A victorious Godzilla then destroys Hedorah’s corpse for good. As Godzilla walks away, Ken and Miki (who survived the attack) thank Godzilla for his help.