Snakes are rarely just animals in the stories I've read. They're almost always a metaphor for something bigger, and power is the most obvious one. Think about the sheer physical threat—the venom, the constriction. An author can translate that into political or social dominance so easily. A character associated with serpents often has that hidden, lethal capability; you know they can strike from anywhere, and their power isn't always about brute force. It's patient, coiled, waiting.
But I'm more interested in the symbolic side, the ancient stuff. The serpent in the garden, the ouroboros eating its own tail—it's knowledge, eternity, cycles of destruction and rebirth. When a modern fantasy or dark romance uses a snake-shifter or a deity with serpentine features, they're tapping into that. It's not just 'this guy is scary'; it's 'this entity understands secrets you don't, and their power is as old as time.' That adds a layer of awe alongside the fear. In 'The Serpent and the Wings of Night,' for instance, the serpentine vampire isn't just powerful; he's fundamentally other, his power tied to ancient, possibly divine, origins.
Honestly, sometimes it feels a bit overdone. The moment I see a snake motif, I can guess the character will be cunning, probably morally ambiguous, and hold some kind of forbidden knowledge. It works, but I wish authors would subvert it more.