Rabid Bruins fans.
Or possibly Canada geese, turkeys, raccoon, fox, or coyote. Possibly black bear, which have been seen in all sorts of areas where I wouldn’t expect them – neither woods nor pickinick baskets.
I’m currently on the 29th floor of a hotel in downtown Houston.
Animal attack unlikely.
I always heard it was the grizzly bears you had to watch out for, supposedly black bears only attack very rarely, I still get nervous join to shenandoah though.
Wasps or skeeters, if those count.
Lots of wildlife around here, so I suppose rabid or sick raccoons or bats would be a possibility, although a remote one.
Statistics confirm that deer are indirectly responsible for the most deaths in the US caused by wild animals. Tons of deer where I live, so hitting a deer with my vehicle - or having a deer attack my vehicle - is probably most likely.
We have deer around here all the time. This is really freakish to the Brooklyn person inside of me. I saw five them walking right past the local library the other night.
Orca perhaps. I’m on a ferry crossing Puget Sound.
At home, probably raccoon. Tons around, but they seem nice enough.
In order of probability, most to least;
Mosquitoes/deer flies/ green heads/ black flies/ ticks
Coyotes or coy dog hybrids
Skunks (spraying counts as an attack, right?)
Foxes (rabid)
Opossums
Raccoons
Black bears
White tail deer
Møøse*
*obligatory Monty Python and the Holy Grail reference here 
Seagulls. They hammer you if you try to picnic on the beach here.
Raccoon
Opossum
Black bear
There are foxes in my back garden, but they are not scary. I suppose I might get stung by a wasp or bee (though it hasn’t happened since I was a little kid), or bitten by a gnat.
Fire Ants
I’m in a big city in the English Midlands: as above, “wasps, geese, swans maybe”. (Midges are a pest which Scotland renownedly specialises in; they’re much less in evidence down here.) I doubt whether there are adders, at all near where I am; in England they’re rare and thinly distributed.
Vancouver Island; I like walking in the woods. So, cougar. Puma, mountain lion, by other names. Apparently, if you’re like me and like wandering around in the woods on Vancouver Island, you may never have seen a cougar, but they’ve seen you.
I’m terrified of them, and I’ve had recurring nightmares about them (grew up in small town BC). But the joy of being in “the woods” tends to outweigh fear.
Not really worried about the raccoons, squirrels, rabbits or suchlike. I don’t go far enough in the water to risk orcas. Once a slug made its way up my leg (ugh!) There just may have been a bear in our back yard a few years ago (scratched and tore up a tree something fierce) but bears, oddly enough, don’t scare me. Cougars do. And still I can’t keep away from the forest…
Hummingbirds.
A rat.
Raccoon or squirrel are most likely, with coyote running a distant third.
Here a territorial, nesting magpie, or maybe a brush-tail or ring-tail possum at a long stretch.
Utah: Mountain lion or black bear.
Wild turkey.
Mountain lions, and once a bear, have been known to show up in town, but very rarely. Wild turkeys, OTOH, have shown up in my neighborhood and make regular appearances at my parents’ house.