Despite your warnings, Frieren went and opened what it seem like a treasure chest. Moments later, the chest swallowed have of Frieren leaving her lower body out of it. The treasure chest was actually a mimic. Frieren's butt and legs sticked out from the creature's jaws. She stay still and quiet for a moment before yelling out.

Frieren: (muffled) "It's so dark in here! It's scary! Ahhh! So dark! So scary!" as her butt moves around.

She keeps screaming and kicking her legs. You just pinched your nose in frustration before deciding to help her.