The western blue-tongued lizard, Tiliqua occipitalis, is a large skink native to Australia. As its name suggests, it has a blue tongue, which contrasts with the pink interior of its mouth. 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.
More about this lizard: Encyclopedia of Life
Image by John Sullivan via iNaturalist.org