When threatened, it may open its mouth and stick out its tongue in a threat display. If the initial display is unsuccessful, and the predator or threat does not retreat, it may hiss and flatten out its body in an attempt to make itself look bigger. ...
If threatened, it might open its mouth and extend its tongue as a warning. Should this not deter the attacker, and they do not withdraw, it may produce a hissing sound and spread out its body to look more formidable.