It's horrifying. It's fascinating. We can't look away.
YouTube user Bettina Turnbull uploaded this video on April 10 of an octopus hotly pursuing a crab. According to the description, she filmed it at Rose Bay Wharf in Sydney, Australia.
The crab puts up a good fight, zigging and zagging across the surface of the water. But the octopus eerily shape-shifts after its prey. As an Imgur user put it, "resistance is futile."
There's something deeply alien about octopuses. To creep you out even more, they're highly intelligent with their own distinct personalities. They can open childproof medicine bottles, play with toys and recognize different humans.
A New Zealand octopus is smart enough to take pictures of aquarium visitors. And they have a well-documented taste for crabs.