And what gun or bow??
I'll start it off:
Island Blacktail with crossbow - 2.5 feet.
Alberta Pronghorn - 300 Weatherby Mag - 12 yards (cut it in half).
NWT Wolverine - 22 pistol - 4 feet (defensive forehead shot).
Alberta whitetail - 12 gauge - 8 feet (back of the noggin when it jumped).
Warthog - Zimbabwe - 45 Colt 1911 - 6 feet face on.
There have been others, but these ones simply came first to mind...
Cheers,
Nog