Do mermaids exist? Or at least one?

Answer

I read from Wikipedia:

The medieval fantasy of fish-tailed mermaids comes from the stories of sailors who thought they saw these creatures in the foam. In reality, they probably manatees or manatees seen: these mammals from tropical waters have a pointed shape; the females also have nipples, which evoke the image of the female body shapes. Not surprisingly, the gullible sailors could make such a mistake.