Long ago, frogs were supposed to stay on land and away from water, so were the other animals. The source of water is sacred and under control of the gods; there was a god that gives away a certain amount of water every day to the animals and the plants to let them survive. To keep the creatures loyal to god, any creature that casted a sin or betrayed the gods will be prohibited to have water and soon die of thirst for punishment.
All the living creatures stayed under control, until one day, a drought appeared on land. Plants stop fruiting and animals start dying. They prayed for more water but the gods just ignored. The animals are angry but there is nothing they can do. Soon, the animals found the one who casted the drought, the sun. At first the sun never mentioned that it is on the wrong place in the sky that too much sunlight killed the animals, it apologized and promised to do a favor to make up for this.
After a short discussion, the animals agreed that the source should never be controlled by the gods again. They sent the frog to the source undetected, and the frog croaked loudly to signal the sun to deliver the hot light directly to the water. The water vaporized into the air and soon condensed into rain. When the gods saw the whole world raining, it was too late.
The gods angrily send a new creature, the snake, to the ground to hunt down the creature that destroyed the source, because they can do nothing to the powerful sun. The snakes killed so many frogs that the only way for the species to survive was to have their offspring in water. The rain had formed many ponds and lakes; besides, the snake was still loyal to the god’s rules that it never goes near water.
To thank the sun, every summer the frogs will croak loudly and have offspring in this safe season for frogs, and the sun will reply by bringing a hot humid weather to the world, which the frogs soon found it comfortable.