The Dark & Messed Up Origin Of Mermaids Have you ever wondered why mermaids have captured our imaginations for centuries? From enchanting Greek sirens to eerie Slavic Rusalki and monstrous Japanese Ningyo, join us for a deep dive into the captivating world of mermaid mythology. Let’s get into it. The typical image of a mermaid is that of a half-woman, half-fish creature. However, the way mermaids are depicted can vary depending on where you are in the world. In the Western world, one of the most significant influences on mermaid lore comes from Greek mythology, specifically the sirens. While sirens are often confused with mermaids, they are more bird-like than fish-like.