Info from Wikipedia: These two Glaucus atlanticus, a species of nudibranch, were washed up on Surfers Paradise Beach in Queensland, Australia. The larger one is about 35 mm (1.4 in) in length. G. atlanticus preys on the Portuguese Man o’ War and other surface-dwelling sea animals. Occasionally Glaucus will feed on others of its kind.
This guy looks like a ship from Star Trek… or so I would imagine if I ever watched that kind of show… The fact that they prey on Portugese Man of Wars makes them that much cooler. The name “sea slug” most certainly does not do this piece of real-life science fiction justice.
Thanks to Josh Attenberg for the heads up.