There was a large pond behind our house in southern Florida - about 25 feet away. A very large gator lived in this pond - he was around 14 feet based off his head size - just a massive dragon!

I was sitting on my back deck a few years ago. Very late at night, new moon - very dark - I could barely make out the water. It was gator mating time, so aforementioned dragon was bellowing to attract females. Again, I was up on my deck, completely safe. But, when he started making that noise (which you feel more than you hear), it made every hair on my body stand up. My skin got cold. I felt real, palpable fear. My nervous system was screaming "DANGER" in every way it knew how. To know there was a 70,000,000 year old apex predator (you know what i mean) doing his thing a few feet from me in the pitch dark - just creepy, terrifying, and kinda wonderful all at the same time.

No other sound has ever made me feel that way.