Back in 2009 I was working nightshift onboard a ship in Nigerian waters. I was stuck where I was, operating the machinery, so I radioed in if someone could please bring me a coffee, because I was sure I just saw a flying dog.
"Oh, those are fruit bats, you'll see more of them" they replied from inside, knowing exactly what I was talking about without needing more details.
And yes, I did see more of them over time; they liked hanging from the back deck work crane when it was not in use. Awesome creatures, and pretty large too.