The Tokay Gecko (scientifically known as Gekko gecko) is a nocturnal tree-dwelling lizard ranging from northeast India and Bangladesh, throughout Southeast Asia to western New Guinea. Its native habitat is rainforest trees and cliffs, and it also frequently adapts to rural human habitations, roaming walls and ceilings at night in search of insect prey.
Although present in Malaysia it is rarely encountered there, in fact I've never seen one in Borneo. In the Philippines it is quite common, and many rural house have a resident Tokay. This photo of a single male is taken in a house in Pagadian.
Males are said to be very territorial, and will attack other males Tokays as well as other Gecko species. They are solitary and only meet during the mating season. Females lay clutches of one or two hard shelled eggs which are guarded until they hatch.
I took the second photo inside the historic Makahambus Cave in Cagayan de Oro in 2006. It seems the adults as well as a whole brood of youngsters are helping to guard the clutch of eggs!
Tokays are renowned for their their loud vocalizations. Their mating call, a loud croak, is variously described as sounding like tokeh or gek-ko where both the common and the scientific name as well as the family name Gekkonidae and the generic term gecko come from.