Physalia physalis, commonly known as the Portuguese man-of-war or bluebottle, lives in warm waters worldwide and is famous for its painful stinging tentacles up to 50 meters (165 feet) long. The gas-filled float and crest at top acts like a sail.
Contrary to it’s appearance, this is not a jellyfish. They are siphonophores, colonial marine invertebrates. So the picture above is in fact of multiple organisms, called zooids, and not one animal.