A baby tortoise is called a hatchling. It uses its egg tooth to break the shell of the egg and emerge. Hatchlings are very vulnerable for the first few days of life, and rely on the embryonic sac for nutrition until they are strong enough to find food.
Sometimes hatchlings wait to emerge from the shell until all of the embryonic sac absorbs. If the sac is ruptured, the hatchling can bleed to death or die of infection. In the wild, many hatchlings are eaten by predators, such as seabirds, but many zoos and conservancy organizations raise baby hatchlings to maturity.