Trick question...Kinda...Any aminal will GO DOWN if double lunged!!! Period!! Will he run a little???Maybe...But as far as toughest species to hunt well again it depends...The Mulies as tough to hunt as the terrain can be killer...I mean those mountains in the West sure are harder to climb day in & day out,,,than most Whitetail Country....BUT to kill a "wall hanger/trophy" the Mulies are MUCH easier than a Whitetail!!!! I"ve hunted Wyoming Many times and killed some great bucks and passed up many great bucks hoping for that TRUE MONSTER..Than you turn to the Whitetail....It is a hard deer to hunt and be successful at killing "wall hanger/trophies"....I,ve been lucky or more to the point delingent at hunting these BIG Whitetails....No I,ve not killed a B &C Record Book Whitetail....because South Carolina does not produce many,,,BUT I have killed several that get as good as they come for SC....And for those who know I DO NOT LIVE IN THE LOW COUNTRY OF SC WHERE THEY SHOOT'EM OVER A CORN PILE...I have hunted there however and will say that it is still hard to kill a big buck over a corn pile,,,BUT much easier than when not over bait....