I know that's not how you spell 'kaleidoscope', it's wordplay. This is a male veiled chameleon, Chamaeleo calyptratus. Based on comparisons of his scales to photos in the National Zoo group, www.flickr.com/groups/usnationalzoo, I've decided he is indeed from the National Zoo and not the Baltimore Aquarium....finally.
Flickr is almost certainly the best online photo management and sharing application in the world. Show off your favorite photos and videos to the world, securely and privately show content to your friends and family, or blog the photos and videos you take with a cameraphone.
Uromastyx - Spiky-Tailed Flat, Muscular Desert-Dweller
Uromastyx - This spiky-tailed lizard of the desert can come in some bright colors. It can use its tail in defense but prefers to bask in peace.