Fleas!

They are very fast, and kill zone is way too small.

seriously, prarie dogs.!!!

got them in the field behind my house.... cant wait till all the snow melts

Samething i was thinking of.

Cam

Agree with you David!

The Southwestern jackelope.
Tough to kill, small kill zone, and if you miss, he's on you like white on rice.

Bighorn sheep.

i limited here since i have only hunted deer ,turkey ,hogs in big game but will bear huntin this fall . so i have to aint nothin harder than huntin an ol wiley whitetail buck thats in his prime .

groundhogs are some weary and hard to hunt sobs too.

Chupacabras! really, really hard to find!

Toughest to kill: mountain goat, without doubt!
Toughest to hunt: hard to say but I'd have to lean toward trophy whitetails.
My experience with "anything that can eat you if you miss" is that it ain't all it's cracked up to be, at least not in North America, Africa may be a different story...