After many years of fishing very close to brown bears and black, moose, caribou, even sheep, and mountain goats, I have had a whole slew of very close encounters... In two weeks this spring we had at least 200 encounters with Kodiak brown bears (many were the same bears repeated) .
A few years ago we had a Kodiak bear pop out of the brush no more than 25 yards from us and I stood him down and made him go around us because we had a bunch of fish and did not want him to get the idea we could source them for him. It all happened pretty fast and when the bear was moving away I recognized him as a very big bear that had been very aggressive towards me in the past... Enough so that I simply left the stream when he showed up. As he was going away he suddenly had a very ugly bowel movement and I realized he probably was grumpy atop his reputation (with me) as a dominant alpha critter.
As a kid my father left me to direct him to a mountain goat from the lake side with signal flags. After he killed the goat I went fishing and stumbled onto a sleeping boar brown bear at very close range. I backed out as quietly and quickly as I could. I do not think the bear even woke up.
Last time I was out we saw a ridiculous number of porcupines... Enough we lost count, but well over a dozen in a single day.
Many years ago I watched a fox fishing for pike in flooded grass. He caught several and ate them right up.