While this trope seems unfair to those who like reptiles, its origins can be at least partially explained:
- There's an Otherness issue. Their bodies are often cold, hard and scaly, while as mammals we tend to prefer things warm, soft and cuddly. Snakes in particular, with their legless bodies and unblinking eyes, can seem just wrong to some people. On another front, reptiles like lizards, alligators, crocodiles and snakes generally don't show emotion besides "angry" and "startled", and they lack demonstrated affection compared to mammals and birds, which alienates them even more in our eyes.
- There's the unfortunate fact that some reptiles are in fact dangerous to humans (despite the fact that hippos kill more people than crocodiles). Larger reptiles eat large mammals. Additionally, some snakes are venomous. Stemming from this are superstitions and stories created to try and combat that danger, or simply entertain: lurking menaces that can slither into your hut and envenom your children make for great baddies. The forked tongue of the snakes was once believed in some cultures to inject venom instead of their fangs, and in some languages being "forked-tongued" means being untrustworthy. Other dangerous creatures such as lions tend to be big, strong and charismatic and are spared such hatred.
- And, of course, there are many Herpetophobes out there, justified or not (it's a healthy fear if you live in parts of Australia; silly if you live in parts of New England). Writers are quite keen to jump on any common fear in their audience..
As with What Measure Is a Non-Cute?, it should be noted that this view varies by culture. It is largely played straight, especially with snakes, by Europe and North America and a few other cultures. In many other parts of the world (particularly Asia), on the other hand, snakes are associated with various gods, as well as being seen as symbols of immortality and fertility. In quite a few Bollywood movies, cobras are a force for good, killing evil villains.
- Back in the days of Ancient Greece, the trope was Zig-Zagged. A snake shedding its skin was assumed to be dying and being born again: as such snakes were a symbol of healing, immortality, and protection, as demonstrated by their presence on the Caduceus
and the Rod of Asclepius. On the other hand, there were still many abhorrent reptiles: The Lernaean Hydra and the demon-god Typhon are outright evil, while the hundred-headed Ladon and unsleeping Colchian dragon were neutral guardians that nevertheless opposed Greek heroes.
