YOU SEE THAT BIRD CARRYING AN ELEPHANT?
Yeah, people believed all kinds of things. I'm done writing about The Headless Horseman and am diving tomorrow into One Thousand and One Nights stories, specifically, the ones about Sinbad the Sailor and his adventures, one of which includes him landing on an island full of odd creatures that were eaten by giant Roc birds. They were so huge, they'd snatch and carry off an elephant like that.
What you see above is a 1690 painting by Franz Rösel von Rosenhof. Quite an imagination he had.
However, if you dig deeper, the original story about Roc bird came from an Indian story about a human-eagle Garuda and his fight with Naga. Naga literally means both snake and elephant. I suppose the trunk is what confused them.
I would read those stories, and my eyes would grow huge, and I'd imagine all those beasts and animals chasing me and eating me and...well, that is why things eat people in my books. Blame Islamic Golden Age coupled with a fervid imagination of a little Soviet girl.