Why the 'Lion' of Judah?

I never appreciated what a 'lion' really means until I encountered one on safari in Africa.  Lions have absolutely no fear.  The one I speak of came toward us, walking with confident deliberate strides, right down the middle of the road as if our big Jeep didn't exist.  Passing within a few feet of us, he didn't veer one inch or even cock his head to look at us.  A lion knows that it is the king of the land.

Kruger National Park, Sept 2008