* On various occassions, Snape is compared to a bat. Coincidence?
* When Snape temporarily filled Lupin's position as DADA teacher:
- He made them write a werewolf essay, and Lupin turned out to be a werewolf. Lupin then had them do an essay on vampires. Payback, perhaps?
- Hermione points out that they haven't reached the werewolf chapter yet. Then why would they be learning about vampires, seeing as they would most likely be in the same part of the book.
* You probably wonder how he gets around in sunlight. Well think about it :
- He is a potion master, could he not whip up some sort of sun protector? He creates a potion for Lupin's werewolf problem, why not a potion for his sun problem?
- His hair and face are often described as greasy. This is the symptom of one whom is obligated to wear a constant coating of special sunscreen.
* In the third film when Lupin became a werewolf, and Snape came out of the tree, is it just me or did it look as if he wasn't the least bit scared or confused. What does he have to be afraid of if he's a vampire?
* In the first film, he senses Harry under the invisibility cloak while he's threatening Quirrel, yet Quirrel notices nothing. This may have to do in part with Harry's loud breathing, but take into consideration the third film. When Harry spies on McGonagall, Fudge, and the barkeeper, he is breathing really loudly, yet no one notices him. A vampire's senses are supposed to be sharpened.
His Father -
When Snape teaches Occlumency to Harry in book five, a memory is revealed where he is found crying in a corner while his dad yells at his mom. Perhaps this has caused his father to become his worst fear.
A Cross, Garlic, the Sun, Stakes -
If he is indeed a vampire and J.K.Rowling falls in with the traditional vampire, Snape should fear these things.
Voldemort -
If he is the one that has "left him forever", than Snape might be afraid that Voldemort will find him.