This colorful critter is the Blue-headed Tree Agama (Acanthocercus atricollis) and its bright colors aren't to tell predators it's poisonous (because it's not) but they are used to attract the ladiiiiesssss. These lizards reach a maximum length of 15 inches and during the breeding season their blues and golds intensify.
To attract mates, the males will repeatedly bob their heads up and down [suggestively ;)] as if saying "Ya, yaaaa you like this baby." Or something along those lines. Luckily for the boys, they don't have to worry about a single female giving the A-OK. These guys are polygamous and males may hold six or more females in their territory for breeding. So if one says no, there's a good chance another will say YES!