My best target might be the Mt. Lion, or any deer.

My worst target has always been the little african Black Buck. No idea why. I see it and just go.........[:'(]Javelinas are a close 2nd.
Another target that is tough is the walking brown bear McKenzie. It has a very small 10 ring in relation to it's size and not much definition to pick a spot. Same with the Russian Boar.