Tild and Mukr, twin brothers with wings, lived on Mount Katarangre in peace and friendship with its inhabitants. One day a huge and terrible spider, the Octopus, appeared here. He used to be a little spider, but one day he crawled into a crater with geysers, fell into a geyser with magical water and turned into a bloodthirsty monster. He killed and devoured any animal or bird. Panic seized Katarangra. Tild and Mukr, and their bat friends decided to get rid of the monster. Exposed to mortal danger, they set predatory hornets on the spider. Fleeing from the wasps in the crater, the Octopus fell into another geyser with magical water, became small, and the mouse Mooney ate him.