THE KING COBRA, OPHIOPHAGUS HANNAH (CANTOR) IN SINGAPORE (REPTILIA: SQUAMATA: ELAPIDAE)

The king cobra or hamadryad, Ophiophagus hannah (Cantor), is a distinctive snake. The adult is brown or olive above with scales dark-edged especially on tail and posterior body with traces of whitish crossbars (Tweedie, 1983: 116, 117; Das, 2006: 64). The throat is orange-yellow with irregular blackish markings, and the belly greyish-brown. The young, at least up to about 60 cm TL (total length), is dark-brown or black above with many white or yellow crossbars that are narrow and chevron-shaped with forward-pointing apices. The head is black above with four white cross-bars. The head and body are white below, with the ventrals and subcaudals bordered with black. The dorsal scales are in 15 rows. There are seven upper labial scales, with the third and fourth upper labials in contact with the eye, and the third upper labial touching the posterior nasal. A pair of large and diagnostic occipital shields are found behind the parietals, with the occipital shields in contact with each other at the mid-line. The underside has 215–264 ventral scales, with the anal shield entire. There are 80–125 subcaudal scales, with the anterior subcaudals single and posterior subcaudals paired. In the field, the king cobra is easily confused with the keeled rat snake (Ptyas carinata), but its larger head, smaller eyes, its pair of large occipital shields, and, when harassed, its habit of rearing up the anterior one-third of the body with neck flattened dorso-ventrally, are unmistakable.