I have had a few minor threatening situations.
I think the most dangerous one was actually a rut crazed WT buck.

Had just shot and was field dressing a WT buck (the one in my avatar actually), and I heard a commotion and some snorting in the woods just out of sight. I grabbed my rifle and walked in to see what was going on.  Another WT buck (medium 4x4) was advancing toward me threatening me.  His tongue was out all over the place I remember as he stomped the ground and put his head down and antlers toward me, even yelled at him a few times.  I had that orange tarsal gland scent on me from the dead WT I was skinning and that likely triggered him.  He was nuts and only a few yards from me and not backing down one bit.  I had the rifle ready to go and thought I might have to use it when yet another buck appeared behind the one giving me the gears.  The nuts buck wheeled around and took off after that buck and in a minute or so I could hear them fighting back in the woods.  That buck was truly worked up and capable of doing some serious harm I think.

I had a particularly scary encounter , one night in
GP ...big cougar.....she was a tough one ,
But I talked her down !
Now as for hunting , a fisher scared the hell out of me ,
griffon gave it a wide berth...this was a couple of miles
From the # 1 Hiway....rare sighting ...

I have been lucky but a good friend had a very close call with a cougar while calling elk.
He pulled the trigger just as it was pouncing and he could touch the carcass with his barrel from the spot he was sitting in when he leaned forward.
Scary close call.
Be aware we are not the only ones hunting and dont forget they like to ambush from above sometimes.