What was your biggest non-boss scare moment in your first playthrough?

Mine would have to be seeing the undead dragon in the Valley of Drakes. I discovered the place from the darkroot basin entrance and when I was making my way up the ledge on the side I saw that huge thing on the ledge. I had no idea what it was and so I shot it with my bow from pretty far away (wasn't close enough to see the face) and when it moved I noped the fuck outta there.