Head down the warm tunnel

There's a cold breeze blowing through most of the tunnels, but one passage seems to have warmer air flowing from it. Perhaps it's not far from the surface and the warm air is blowing in from outside.

You wander down the path a while, but you see no daylight. The air is getting hotter though, and more humid. You start to hear squelching noises, and start to notice that the walls seem to be taking on a different texture. You continue onward hurrying as strange noise seems to be following you.

The air grows thick and hot, and you stop long enough to notice that the tunnel you're in has fleshy pulsing walls. You seem to be inside some kind of creature connected to the caverns. A large worm-like creature descends from the ceiling, slowly pointing in your direction as a lot of little wiggling fingers flail around the tip.