I would tell Alex not to be afraid. Many animals we keep as pets will bite or claw us for reasons that aren't immediately apparent.

I've known the sweetest, gentlest dogs, who were startled and nipped someone. They didn't mean to hurt them; it's just the dog's way of saying, "something scared me."

I've had cats who were very loving, but every once in a great while they just suddenly got mad at something, and scratched me. Not bad, mind you - just enough to get my attention.

Snakes are the same. Even the calmest snake will sometimes get scared by something and nip at us. It doesn't mean they want to hurt us, and I'm sure Nergal didn't want to hurt you.

I hope Alex and Nergal are both OK, and can make up and be friends.