Literally, the word Animal comes from the Latin word "animalis" which contains two words (breath, spirit), And it turned into "animal" in modern English. In English it stand for meaning 'Living Orgasm'

Animals are in general, perceptible existing living creatures that are multicellular, eukaryotic and can move easily.

The creation historical story of living animals is too much long process in which billions of years passed to evoluted. See details in Starting Of Life In Earth

The animal world is divided into three groups based on habitat:

• The Flying Animals
• The Land Animals
• The Oceanic Animals

The lives are important for the earth, not animals. Every animal has its own preferred life, a spirit also. So it is unseemly for any wise mind to despise a life. Some importance of Animals:

• Ecosystems, According to new research by the National Geographic society, if all animals on Earth are extinct, the Earth's ecosystem will be destroyed in 9-10 months. Birds, predators, wild animals, insects and snakes keep our ecosystem alive and vibrant.
• Food Web, Earth's Food Web Totally depends on Insects. See details Food Web System
• Climates, Earth's climate is highly related to Mountains and Oceans, and mountains and oceans depend on weather and trees, and weather and trees mainly depend on birds, insects, animals etc.
• Natural disasters, Same to above