I was on an island in the middle of the pacific, doing my first ever project away from home. There was maybe 30 people on this 3mile island and most had finished their respective jobs and headed in to camp for the night. my job at the time was to hike around after dark to make sure the coconut crabs weren't eating all my ant traps. They are shy, curious creatures and will steal stuff when you're not looking to rip apart and sniff or chew so that night I had a large male crab as my only company in the palm forest. When we reached a break in the trees I stopped and looked up at the stars for a second. And froze. Somewhere, in the pitch black darkness overhead was the freakiest goddam sound and it was getting louder. It was coming towards us. It literally sounded like a fussy baby crying. Overhead. Flying towards us. I looked at my crabfriend and he looked at me with the same freaked out expression, and I bolted. I ran straight for the research tent. Some time before I reached it, my brain must've kicked back on, be cause the first thing I said to another person was: "is there a bird that sounds like a flying ghost baby???" Yes. There is, it's called a Wedge Tailed Shearwater and it freaked me the f*k out.
Here's a link to an mp3 of its call(I'm on my phone so forgive me if it doesn't work):