By defensive display you mean making its jowl bigger?
It is a whole body posture, the monitor tries to look bigger and keeps its ground... at that time, must be careful, not too close cos it can whip its tail. It is quite rare behaviour, usually they just flee....
Thanks for sharing! Such a cool find that Gerarda prevostiana! Such weird behaviour
Thanks Tim! yes, a rare finding... BTW, Cantoria violacea is the rarest of all... Never seen it personally.
I have more pics of my stay there, but mostly they are common things others have already often posted (from Malaysia). If I have some free time I will try to update some good shots (notably frogs, whip snakes, spitting cobra)...
Best,
Guillaume