Otocryptis nigristigma is distinguished from Otocryptis wiegmannii by having a gular sac large, extends from chin to half way down trunk, absent in female, body scales unequal, carinate and larger dorsally. The body color is changeable from coffee brown to blackish brown, head blackish brown. A distinctly black patch presents laterally on dewlaps of males (Bahir & Silva, 2005).

Otocryptis nigristigma is widely distributed throughout the dry zone of Sri Lanka up to 450 m elevation. This species is endemic to Sri Lanka. The female digs a nest hole in the ground and deposits 4 eggs in October-January. The eggs are 10.1-11.6 mm long by 5.1-6.2 wide (Bahir & Silva, 2005).