An "egg tooth" is a small, temporary structure found on the snouts of some reptiles, birds, and mammals. It helps these animals break through their eggshells during hatching. The egg tooth is usually made of a hard, keratinized material and is often pointed, allowing the hatchling to chip away at the shell. After hatching, the egg tooth typically falls off or is absorbed by the animal's body, as it is no longer needed. This adaptation is crucial for species like turtles, birds, and crocodiles, enabling them to emerge from their eggs and begin their lives outside.