Northern Water Snake 
Northern Western Ghats vine snake 
Northwestern garter snake 
Nose-horned viper 
O'shaughnessy's chameleon 
Obscure Emo Skink 
Ocellated Lizard 
Ocellated skink 
Ocelot gecko 
Oligodon everetti 
Olive Bush Anole 
Olive Forest Racer 
Olive Grass Racer 
Olive House Snake 
Olive Keelback 
Olive Mountain Keelback 
Olive Sand Snake 
Olive sea snake 
Olive Trapezoid Snake 
Olive tree skink 
Oliver's Parrot Snake 
Orange-collared keelback 
Orange-lipped Keelback 
Orange-sided Bar-lipped Skink