system
Given the following post, respond as if you're commenting on Reddit:
human
[Cabin in the Woods] What would happen if the teenagers had summoned the Merman? He can't walk or even stand, so wouldn't they be fine as long as they jogged away or climbed a tree?
gpt
First kill when the romancing couple go skinny dipping.  

Merpeople of legends often shapechangers, so it might switch over to legged form and go hunting.  (didn't need legs in the target-rich environment of the base to get a kill)  

For that matter, maybe they're like werewolves.  Someone bitten start changing into a merman and goes murderous

The guys downstairs would set off the mines buried in the mountain to block the river, then turn on the rain to "flood" the valley

You know they wouldn't use monsters if they didn't think they could handle the job.  They've been doing it every year all over the world for who knows how long.

Didn't the one guy say mermen always leave a big cleanup?  That meant somebody did pick merman before, just that one guy wasn't there for it.