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  ......what? Really? No one in this thread, not one person in this entire fandom realized that Zubat's tails are supposed to be vampire coattails?
Zubat's dex entries say how it gets burned if it goes out in sunlight. It and Golbat are supposed to be vampire bats, that's why they're Poison Type. I know people say Zubat is Poison just because "Dark didn't exist yet/generic bad guy Type for villains", and yeah....kinda. But also the idea is they're Poison because vampyrism is like a disease. It corrupts you, it infects via bite like a venom does. Vampyrism infects you and leeches on your vital energy like a poison does.