Well, Elephants can be great in earthly wars as well. The Persians and several Asian nations have what we call war-elephants. Alexander the Great is supposed to have coped with these elephants.
And to how they might be scary, well, several Latin texts state that Phyrrus (A Greek having war with the Romans) had brought an Elephant with him to Itali to scare the Roman Commander. And according to the text I had to translate about it at school, they were pretty damn scary in the eyes of the Romans....
