Introduction to the Tropical Rainforest: The tropical rainforest is known as the "Lungs of the Earth" because it contains rich species and is a paradise for biologists, geographers and explorers in the world. Walking into the mist-shrouded rainforest with sweet air, you can explore tree-climbing frogs, insect-eating grass, color-changing lizards, walrus fish from the Amazon weighing hundreds of kilograms, and giant single-tree trees. Banyan trees and various exotic flowers and plants make people marvel at the beauty and magic of nature.