The largest octopus weighs about 15kg (Octopus dofleini). An Octopus has three hearts and it can squeeze through a hole the size of a 10-cent coin. Hapalochlaena species can inject enough venom in one bite to kill several adult humans. They can adopt a two-tentacles “walk” that frees up their six remaining limbs and makes them look like an armed vehicle.
There are about 300 species of octopus identified. The Giant Pacific Octopus weighs about 33 ponds.
Octopus have three hearts. They have a systemic heart and two branchial hearts. Octopus blood is blue and they have nine brains.