Blue headed Tree Agama/Southern Tree Agama

That and IUCN's map look quite conservative for RSA. But many on-line references including http://www.biodiversityexplorer.org/reptiles/squamata/agamidae/acanthocercus_atricollis.htm demonstrate Acanthocercus atricollis extending further south into the country including the area of this spotting.

Please confirm! They seem to be quite variable. See also: http://nl.wikipedia.org/wiki/Acanthocercus_atricollis Other distributions map show the species going further into South Africa.