Tokay gecko (Gekko gecko) with its mouth open. This small nocturnal arboreal reptile is found throughout the Indian subcontinent and South-East Asia. It is one of the largest of the geckoes, growing to a length of around 35 centimetres. Like other geckoes, the prominent toes of its feet have fine hairs on them, allowing it to climb and cling to vertical walls and overhanging surfaces.