Bobcat.
last season I had a button buck within arms lenght of me when I was in a natural ground blind. I did slowly reach out and slapped his butt, he jumped spun around snorted and stamped his hoof.
His mother and twin sister where within 10 yards and the doe just looked up straight at me or should I say through me for a minute or so and went back feeding.

That has been the biggest buzz I have had hunting in a long time.

On the ASAT web page there is another close encounter story I had.
That was also posted on here.
In short I had a group of does and fawns feeding in front of me when a buck grunted so I grunted back at him and forgot about the doe' s.
In all the excitement of calling a buck in one of the does went looking for the mystery buck and came in the back of the blind which I had cut out of a small cedar grove.
I went to pick up the call one last time to get him into the open and I was hit by deer snot on the back of my head and a very loud snort her head was only inches from the back of my head when she picked up the movement of my arm as I raised the grunt tube.
That morning is as close as I want to get to having a heart attack.