What is strong and hard like a bone but flexible like rubber and is found in your ears?

The material you're describing is cartilage. It is a tough, flexible tissue that provides structure and support to various parts of the body, including the ears. Cartilage is strong and resilient, allowing it to maintain shape while also being flexible enough to withstand bending and pressure. In the ears, it helps form the structure of the outer ear, known as the pinna.