Octopuses are masters at flying under the radar, changing their coloration and texture to match their surroundings in seconds.
But today, this intelligent invertebrate is in the spotlight—it's International Octopus Day. (See "Journey of Octopus Discovery Reveals Them to Be Playful, Curious, Smart.")
Click through for pictures of these stealthy animals, which can be found in wide-ranging habitats from the deep sea to coral reefs, such as the above octopus seen in the Bonin Islands near Japan in 2008.
—By Jane J. Lee, photo gallery by Nicole Werbeck