Gecarcoidea natalis, commonly known as the Christmas Island red crab, is a species of land crab native to Christmas Island in the Indian Ocean. This crab is notable for its vibrant red color and plays a crucial role in the island's ecosystem. Adult crabs can grow up to 11 centimeters in carapace width and are primarily herbivorous, feeding on fallen leaves and fruits. The species is famous for its annual migration, where millions of crabs move from the forest to the sea to spawn. This event typically occurs during the rainy season, highlighting the crab's unique life cycle and its dependence on environmental conditions for reproduction.