They have three hearts: two of them pump blood to their gills, and the third pumps blood to the rest of their body.

They can change their skin's color and texture in seconds to blend into their surroundings.

Octopi are super intelligent - they've been known to solve puzzles, get out of mazes, and open jars, and one even escaped from its aquarium into the ocean.

They have eight semi-independent arms, each with its own set of neurons, meaning they can each explore its environment independently from one another and make its own decisions.