These species of agamid lizard are native to China and mainland Southeast Asia...but I understood that they are locally extinct in Hong Kong. However, more and more are being seen out and about, and it is understood that they have now established breeding colonies. It is a matter of debate if they actually were native here in the past.
These are the lovely Chinese - or green - water dragon (Physignathus cocincinus). They make great pets and perhaps quite a few have escaped or been deliberately let go, as we are seeing more and more of them on our walks. (Re-)establishing a population is perhaps not a bad thing, and they should not upset the local ecology.
Here it is sunning itself on a pipe, halfway up Tai Mo Shan.
It is also known as the Asian water dragon, Thai water dragon, and green water dragon.
oh, and the same one, with a different angle. Actually, I saw two at this location.
Which animal has a third eye?
Like other reptiles, these skinks are "cold-blooded" — ie: they are ectothermic animals, which means that their metabolism cannot regulate their body temperature. So they often bask in the sun to be able to warm up and are active mainly in the morning and evening, staying under cover during the hottest hours of the day to avoid overheating.
Like many reptiles the Chinese water dragon possesses a small, iridescent, photosensitive spot between their eyes: the pineal eye; or sometimes referred to colloquially as the third eye. It is thought that this helps regulate body temperature.