What’s really fascinating about this guy is that it lacks the color-changing cells, or chromatophores, found on many cephalopods (the group that includes squid, octopods, cuttlefish and nautilus), so they can’t change their color to blend in the way other cephalopods do.

Did you know? An octopus is better called an octopod. “Octo” means eight, and “pus” means mouth, but “pod” means foot. These eight-legged critters only have a single mouth!

Known for their ability to blend in with the environment, chameleons have been famous for their color-changing abilities since Aristotle first described them over 2,000 years ago. Most of the time, chameleons are shades of green and brown. This helps them blend in with the background. But sometimes they need to communicate with other chameleons. Males fight other males. Females let males know when they’re not available to mate. When they do, drab goes by the wayside.

Swiss scientists studying panther chameleons found they have a layer of super-tiny nanocrystals in the outer layer of skin. Nano mean one-billionth, so these crystals are only about 0.000007 inch across. Talk about tiny!

When a chameleon is relaxed, the nanocrystals are arranged in such a way that they reflect blue light. The layer of skin beneath the crystals is yellowish. As the blue and yellow combine, we see shades of green. But when the chameleon gets excited, the positions of the crystals changes. This, in turn, alters the color of the light reflected by the crystal. And the calm green chameleon turns yellow and orange, sending a clear signal to his competitor.

Want to see the color change in action? Check it out here.

Did you know? A chameleon’s tongue shoots out of its mouth at a whopping 13.4 miles per hour (21.6 km/h)!

Want to know more? Check out the original research paper.