Sadly, the question isn't entirely facetious for me as I have had the misfortune of facing several animals in combat over the years...
I've killed and eaten two rats and a cat out of necessity while homeless and have twice been assaulted by turkeys over the years.
One had apparently claimed a highly trafficked public area as its territory, and felt I'd challenged it. On the off chance you ever have to defend yourself against a turkey, a couple good swift kicks to the chest area will likely dissuade the bird without hurting it too much.
The other made an ill-fated attempt to fly across a highway and ended up coming through my open driver's side window. If life were a comedy film, it would have been hilarious to see, but attempting to subdue a panicked/enraged turkey in an enclosed space while driving a vehicle at highway speed and trying to steer with my knees isn't something I wish to repeat. As far as I'm aware, the bird survived the encounter with only a few missing handfuls of feathers.
The largest animal I've unfortunately had to fight was a German shepherd/Doberman mix dog. I won through a combination of knowing the animal's preferred tactics and how to counter them, some decent reflexes, and a hell of a lot of good luck. Regretfully, there was only ever going to be one of two endings to that encounter... I'm still alive.
Does Cow-Tipping count as combat?
It is physically impossible for a single person to tip a cow, and there isn't enough room on a single side of the cow for the number of people required to be able to push it over. Plus, cows are usually very placid animals but even the most laconic of them won't stand for anyone making multiple attempts at such foolishness - if one is fortunate, the cow will simply move away. If not, the person making the attempt is going to be severely injured.
The only way to get a cow off its feet without using tools or rope is to use leverage on its head to convince it to lay down on its side like cattle ranchers do when branding them...
