The Diadem Snake (Spalerosophis diadema) is also known as Royal Snake. Its head is longish oval; eyes are small with round pupils and golden iris, which is often tinged brownish or reddish. Its body is compressed, stout, tapering sharply towards neck and gradually towards tail and its tail is less than one-fourth total length. There are two varieties of Spalerosophis diadema. One is light brown or fawn in color with three sets of large dorsal spots, median row roundish or rhomboidal or as short transverse bars, from nape to tail that are alternate with smaller spots of the lateral series. Its head is light brown, spotted, or mottled with darker markings. There is a band between its eyes and a quoits-like mark on parietals that are connected to each other. Its belly is white in color. The markings on its body become obscure with age.
The other one is pinkish buff or pale brown, which is lighter on the flanks. Some scales are deep maroon and are irregularly disposed. Its head and neck are strawberry scarlet in color that is merging or sharply divided. Its belly is rose in color and is spotted crossways. The two races are also considered as two distinct species.
Spalerosophis diadema inhabits in semi-arid and parched areas. It usually hibernates in the crevices between stones in winter and as the sun gets hotter, it emerges for basking. At the least sign of danger, it retires into its stony refuge at the least sign of danger. Spalerosophis diadema feeds largely on rodents.