Octopuses (or octopi, both are technically correct) are renowned as one of the smartest animals alive. With no bones except for their sharp beak, they can fit through almost any hole or crevice. Their skin can change colors to blend in with their surroundings, and if found by a predator they can run away quickly, spray ink, or even amputate a flailing limb as a distraction. Different octopuses can do a variety of amazing things; the coconut octopus (Amphioctopus marginatus) has been known to travel on two limbs, and even use coconut shells for shelter (hence the name). This particular species of octopus, the blue-ringed octopus (Hapalochlaena lunulata), are extremely venomous, and produce a neurotoxin that causes respiratory arrest and motor paralysis in a human within minutes of a bit, which then leads to cardiac arrest. The beautiful blue rings light up as a warning to potential threats to not touch it- it will kill you.