The crocodile is the world's largest reptilian predator, but it's no natural-born killer. Each crocodile enters the world an exact replica of an adult, but four thousand times smaller. When a hatchling emerges from its egg, it's lucky if it can manage to survive for weeks, but its first instinct is to hunt. And a hatchling has simple hunting guidelines: If it moves, it's lunch. It will target anything small enough to swallow, but actually catching prey with its jaws takes practice.