The rough cave tunnel gives up its secrets but uneasily. After a few minutes you hear and see nothing from beyond the gate. Eventually, you push it open and enter.
In the cave beyond as you get closer, you see it lying coiled in the strangely cool cave. It moves slightly at your approach. Monstrous and serpentine, its two great fangs protrude from the upper jaw. Strangely, it also exude an unnatural chill noticeable to anyone in close proximity. It is large enough to swallow a deer, or a man. Then you see another. Maybe a third beyond that.
Do you want to try and fight it, or sneak past *?
* Humans picking their way through the chill, serpentine bodies must make a Challenging (D2) Animal Handling test or an Average (D1) Stealth test to avoid rousing the creatures.