Soft, white and clear-skinned
It was fair to say that getting eaten in these tunnels, would be a pretty dumb way to die, so Andena switched to one of her bodily forms which assured an extra pair of arms.
This body was more tolerant against common elements or issues, like exhaustion and physical damage. With the extra pair of arms, she felt comfortable to prevent any projectiles even, which could be tossed against them.
"Don't wanna know how tough the spears are down here," She thought.
While on that topic, she started thinking about the guide's choice of words, just when the same lady had left to hunt. She was suspicious about the whole hunting idea, because the guide didn't have a weapon with her so far!
Perhaps these people hunted while they were in their snake-like form, and used their human-like body just to walk around easier. It was plausible, but Andena still didn't fully accept those few reasons.