Why are rhino and elephant haraam?

Answer

For the same reason that pig, fox, wolf, hyena, lion, tiger, snake, tortoise, worms, insects and numerous things are haraam. And, the only reason why these creations are haraam is because the Shariah says they are haraam. As for the reasons and wisdom for these things being haraam we are not aware. As far as we are concerned these animals are haraam because according to the Shariah they are haraam. There are thousands of masaa-il of the Shariah whose reasons are unknown to us.