If you don’t have a strong stomach, you may want to avoid the following video of a huge coconut crab tearing a seabird to pieces, although it doesn’t show the worst moments. This shocking video, embedded at the bottom of this post, features the coconut crab, a gigantic arthropod that thrives on remote islands where it has not natural predators.

The crab is so named because it dined on coconuts, not animals, but in this case the crab was an opportunist and managed to grab a sleeping seabird, which tried unsuccessfully to escape its powerful claws. The struggle eventually attracted other crabs, who also dined on the bird.

Coconut crabs can get to up to three feet across. It is extremely large for an animal that has an exoskeleton, and scientists think it may be the largest an arthropod could ever get with its exoskeleton.