i've shot deer, moose, and bear at under ten feet. It's a thrilling experience, and one that can get you flattened.
I've also walked up on deer that I didn't get a shot at that close.
I was "dogging" we had no dogs that year, so I was walking, making noise, and howling like a deer hound. A young doe stood up less than ten feet from me. I had not seen her in the gloom of the balsam fir swamp I was in.
In one bound she was over a big rock, and out of sight. I was so dumbfounded it took a sec to figure out what had just happened. By the time I got up on the rock, she was long gone.
Probably too small anyway, but the time I had to eyeball her was too short to be sure.