Hello everyone, today is Tuesday and this Tuesday is the first of a new series called Australia's Extreme Creatures.
Life is tough in the animal kingdom and survival depends on being the best at evading predators and finding food.
These animals have developed some amazing abilities and characteristics in their quest to be the best.
Kicking off with the Great Barrier Reef which is off the east coast of this great country in the state of Queensland. It is the largest coral reef in the world at 2300 kilometres.
A coral reef is like an underwater city, built by tiny living animals called polyps. Many species of plant, fish and other organisms live together on a reef. Just like us humans live with other animals and plants.