Portuguese Man o’ War (physalia physalis)
The Portuguese Man-o-War is not a single animal. Instead it has different animals working together (siphonophore). The parts are: float, tentacles, reproductive sytems, and mouth. Because of this, detached tentacles can still sting just as much as the ones attached to the rest.
Man-of-wars are found, sometimes in groups of 1,000 or more, floating in warm waters throughout the world’s oceans. They have no independent means of propulsion and either drift on the currents or catch the wind with their pneumatophores. To avoid threats on the surface, they can deflate their air bags and briefly submerge.
Their tentacles can extend 165 feet (50 meters) in length below the surface. They are covered with venom used to paralyze and kill fish and other small creatures.
(Picture of a Man o’ War from below)