I was hunting in the texas national forest.....some of the hardest hunting in the world i would bet........anyway i worked all summer getting ready.......been hunting the area for 4 years and hadnt seen a buck (just does).......opening morning im sitting there and i see a doe coming up the trail, she has a buck trailing her........maybe a 6 point (woulda been my first buck ever).........and they are like 2 feet from my shooting lane, they both stop and look back..........then like a flash their gone............I am completely stunned, heart sank.......in shock and up the trail comes about a 3 pound Lasa Opsa (sp?) yapping up the trail...........the dog has no idea how close to death he was that day...............

Mostly these critters........never quite like this though.

http://www.bofunk.com/video/2535/brave_squirrel.html

squirrels are obvious. One year I had a stray cat sit beneath my stand all day and meowed for hours. That was a tough day. Actually thought about dispatching it so it would not ruin my hunt, but my ethics were in check that day!

No animal other than myself!!

DOGS!!! This year I had some dogs ruin my hunts a few times. Once I was hunting and a dog came running through. That was bad enough, but then some people following the dog walked off about 100 yards yelling for the dog. I've also left my house in the morning and got into the woods a good ways and looked behind me and saw MY dog following me.

Cats, coyotes, and cows are some other ones. A doe was feeding out in front of me one evening and a cat (not a house anywhere near) walked out and scared her off.

If a 4 wheeler is an animal than i guess you could count that as one for me,

although i have had dogs ruin hunts before, i had a dog chase 5 does right underneath my stand twice in 5 minutes this year, had it not been opening day of modern gun season one of them would have hit the grounda pretty hard, maybe even two if i was lucky

I can't say that a animals has ruined my hunt because I had a yellow dog come in once and told it to get and ran off andabout 15 minutes later a deer came from its direction witch I could have shot.

Possums spook deer up here for some reason, when I was younger I used to have them run deer off of my bait pile, til i exterminated the little duck/goose egg eatin son of a 's. BTW- I no longer hunt over bait now that i have a few under my belt....