The octopus might be the strangest animal on our planet. It has three hearts, blue blood, and nine brains. One brain controls the body, and each of its eight arms has a small brain of its own.
An octopus can change its color and shape in less than one second. It can look like a rock, a plant, or even a poisonous snake. Scientists have watched octopuses open glass jars to get food inside. Some even collect coconut shells and use them as houses.
In aquariums, octopuses recognize the people who feed them. One famous octopus in New Zealand escaped through a small pipe and returned to the ocean. The sea still hides many mysteries — and the octopus is one of the greatest.