Alien-looking sea creatures in spectacular hues of blue, recently washed up on beaches in Sydney, attract with candy contours, only to strike with venomous stingers.
With a sting more powerful than a Portuguese man o'war, experts at the Oceana foundation said, these brightly colored creatures are known by a few lofty names–blue dragon, sea swallow, blue angel–but in fact are a species of sea slug.
