This, according to "plant collector" Frank Horwood, is a Spiny-tailed Uromastyx, found in northeastern Somalia (from Mudug to Bari, maybe?). Uromastyx macfadyeni, the likely species of this example, is, according to a reptile shop in Temecula, California, a sexually dimorphic species with the males being bright sky blue to turquoise green with yellow and tan spotting on their backs. Females are duller, with more tan and brown and indigo blue coloring on their faces and forelegs. They tend to be shy at first but warm up after awhile. Their movements are quick and they are very alert and curious.
They are being sold at a few pet stores, and appear to fetch a nice price because of their rarity. I think they are pretty and interesting (the previous link provides some gorgeous pictures). Growing up in the Mudug region, I recall being in mortal terror of giant lizards (abeeso), big enough to swallow a recalcitrant child--much like their carnivorous cousins the crocodiles. Uromastyx seems to be no bigger than a gerbil, but I was a lot smaller then.