If you are implying that elephants are afraid of mice - I'm sorry to inform you that it isn't so.
"The myth probably came from Roman times when elephants were used for war. It turns out that the biggest advantage was to intimidate their enemy since they were prone to panic and when they did would trample almost anything in their way. Unfortunately that was often your own army if they stampeded the wrong direction".
And as far as a lion or hyena being able to stamped a herd of herbivores - the reasoning should be obvious.
Just imagine you and a hundred of your friends hanging out at the park and just one T Rex showed up - what would all of you do?