I loved the Hell out of this movie when I was a kid. I still love it, in fact.

Anyway, I don't think he hated elephants, it's just that they help people visualize how big and strong a monster is when they fight.

Also, if you can save a few bucks by reusing an elephant-shaped stop motion armature in every single movie, you use the fuck out of it.

I thought (still think) that Harryhausen's talent really shone through with his elephant animations, as a lot of us have some idea how an animal like that will move-- and his elephants are as convincing as can be within the limits of stop-motion (no motion blur, etc.)