Octopuses are magnificent con artists. When trying to escape from the clutches of ravenous predators, they can change the color, texture, and even shape of their bodies to hide in plain sight. It’s an ingenious survival tactic, especially when you consider that octopuses are distant cousins of the slow-moving, easily-duped, garden snail.

Sure it’s hard to think of octopuses as complex creatures. After all, just look at them! Their soft bodies and alien tentacles look anything but human. In reality, octopuses are quite smart! So we really shouldn’t be so judgmental.

In fact, the coconut octopus (sometimes called the veined octopus) is the only invertebrate that is known to use tools—a sign of advanced intelligence. Interestingly, scientists thought that humans were the only species capable of using tools until we discovered that chimpanzees and some birds do too.

But mollusks? Come on! That’s unbelievable.

How do we know that they do? In 2009, scientists observed some very peculiar behavior when studying octopuses in Indonesia. The aptly named coconut octopus would gather coconut shells discarded by humans and awkwardly carry them across the ocean floor—which doesn’t make sense since they could move much faster without the cumbersome, heavy load.

“While I have observed and videoed octopuses hiding in shells many times, I never expected to find an octopus that stacks multiple coconut shells and jogs across the seafloor carrying them,” said one of lead researchers, Julian Finn, in a press release for her study published in Current Biology.

Weirdly, the coconut octopus it the only known octopus in the world that is known to exhibit bipedal behavior when carrying coconut shells—aka “walking” on two legs.

“I could tell that the octopus, busy manipulating coconut shells, was up to something, but I never expected it would pick up the stacked shells and run away. It was an extremely comical sight—I have never laughed so hard underwater,” Finn expained.

See for yourself in this gif shared in Reddit’s “Whoa Dude” community.

After seeing the gif, a marine biologist who goes by the Reddit username Alantha chimed in with a fun fact about how octopuses learn their behavior. (Editors note: Alantha wishes to remain anonymous but confirmed her identity to us privately).

Alantha wrote:

“For an animal that generally (depends on species) only lives maybe two years they certainly seem to learn a lot in a short time! “It’s also interesting given their solitary life style. Often animals that live in groups learn from watching each other’s behaviors and particular behaviors are passed along from generation to generation (such as dolphins using sea sponges to protect their snouts when foraging). “Our friend the octopus learns on its own with minimal contact with conspecifics (same species) and no influences of parental care or sibling rivalry.”

So what’s the purpose of dragging coconuts around? Well, coconut husks are sort of like a suit of armor for the octopus. If danger calls, they can simply assemble the husks together and squeeze their bodies into a makeshift, portable fortress.

Since octopuses wouldn’t be able to crack a coconut on its own, scientists suspect that the octopus build its castle out of dead shellfish before humans settled the coastline.

“The discovery of this octopus tiptoeing across the sea floor with its prized coconut shells suggests that even marine invertebrates engage in behaviors that we once thought the preserve of humans,” said Finn.