Question: At the time that this movie was made, nobody knew what made a werewolf, what could kill a werewolf, or when a werewolf would appear. Who decided that these things could happen?
Answer: Werewolves as a concept date back many years - this film originated many of the current conventions though, so the simple answer to your question is "the writers of this film". See the Wikipedia for more info - http://en.wikipedia.org/wiki/Werewolf.
Answer: All the elephants are credited as "Elephant." The only difference is "Matriarch Elephant."
Sol Parker