The Robber Crab
The coconut crab was the bad guy. They ended up finding the rifle later, and it was crushed. Many reports indicate that the crabs steal cameras and shoes from tourists who carelessly leave them lying around.
Lifespan
Overall, coconut crabs are the biggest land-based crabs and live the longest. They might live 120 years, so Mark probably handled one that was older than him. While they aren’t dangerous, their claws can be harmful; Mark was very lucky!