The Portuguese Man O' War (Physalia physalis), also known as the Portuguese Man-Of-War, Man-Of-War, or Bluebottle, is a jellyfish-like marine cnidarian of the family Physaliidae. Its venomous tentacles can deliver a powerful sting.
Sea Anemone Photograph by Oriana Poindexter. A close relative of coral and jellyfish, anemones are stinging polyps that spend most of their time waiting for fish to pass close enough to get ensnared in their venom-filled tentacles.
Green Sea Turtle eating Jellyfish - Dimakya, Philippines by Ai Gentel --Exactly why it is dangerous for plastic bags to pollute the oceans, because they are often mistaken as jellyfish and kill turtles.