Horror games should have more of this sort of thing.

Imagine walking into a big room and having the entire floor littered with these guys. Different sized ones just scattered everywhere. Whether they even would need to attack or do anything else is debatable, I think they'd be effective enough just sitting there making gross fleshy noises.

Perhaps you walk carefully through them just fine with no conflict at all, and later in the game you encounter the same room. Thinking they'll be just as docile, you proceed with more confidence, only for them to become aggressive as you're stepping through their midst.