Some enemies of the octopus include eels, sharks, halibut, ling cod and dolphins. The octopus uses camouflage to protect itself from predators, which allows it to hide in plain sight. It also releases a cloud of black smoke to cover its escape if it is attacked by an enemy.
The cloud of black smoke, often referred to as ink, also reduces their enemy's sense of smell, making the octopus difficult to track. It quickly escapes from harm due to its ability to expel water through its mantle to propel itself forward at great speed. The octopus has a beak-like jaw and venomous saliva that it uses to defend itself and subdue prey. The octopus also defends itself with its ability to maneuver its soft body into extremely small cracks and crevices. Its most basic form of defense is its ability to camouflage its body, allowing it to hide in plain sight. Pigment cells and specialized muscles in its skin allow it to match the colors, patterns and textures of its surroundings almost instantaneously. It is able to lose an arm to get away from its enemy and regrow the arm later. Two-thirds of its neurons are located in its arms. This allows the arms to perform problem solving tasks independently of the head, even if the octopus is engaged in a separate task. The arms also react to stimuli even when they've been severed from the octopus' body.