Blue-ringed octopus

  The Blue-ringed octopuses (bloo-ringed-oct-to-puss) is the size of a golf ball, but its venom is powerful enough to kill humans. Their diet typically consists of small crab and shrimp, but they may also feed on fish if they can catch them. They pounce on their prey, paralyze them with venom and use their beaks to tear off the pieces.  An individual blue-ringed octopus tends to use its dermal chromatophore cells to camouflage itself until provoked, at which point it quickly changes color, becoming bright yellow with blue rings or lines.