If you're camping, make sure you keep food in airtight containers and not left outside; don't leave any garbage outside, it will attract wildlife such as bears or raccoons.
Raccoons have a strong sense of smell. I once had an one UNOPENED bag of chips in a plastic bag outside, and I thought " the bag's closed its fine" - I was tired of putting everything away in my car. Then, while I was asleep in my tent, I heard a scuffling and it woke me up and scared me; the next day there were scratches through the bag, but he didn't get to the chips. I definitely learned my lesson!
giant water spiders - I hope I don't encounter one of these, I'm terrified of big spiders
bees, wasps - avoid bees nests
I've seen water snakes - apparently they bite, I dove in the water once and came eye to eye with one of them when I lifted my head out the water.
Let's just say I skipped/ran out of the water very, very fast, and he slinked away on top of the water.
bears, cougars, wolves - remain a safe distance from them, 100 metres
goats, sheep, moose, elk, deer - remain a distance of 30 metres
select one here...