This is the Giant Legless Skink, Acontias plumbeus, which is fossorial and feeds on invertebrates (it is also known to eat small burrowing reptiles and frogs). This specimen was photographed at Haga-Haga, a coastal village north of East London (SA). A total of 127 genera and 1 305 species occur worlwide.
Skinks have tight-fitting overlapping, shiny scales. The head is not usually distinct from the head. Tails are easily shed and regenerated.
Reference: A guide to the reptiles of southern Africa by Graham Alexander and Johan Marais. Struik Publishers 2008.