Not so much bad ass, but traumatic:

I was in a pig pen and a massive pig attacked me. Knocked me right on my back and was on top of me. Had a mouthful of my coveralls and was rag dolling me. I tried punching as hard as I could. Nothing. I drove my thumbs into its eyes. Nothing. I tried to choke it. Nothing. I scrambled to find a rock to club it. Nothing. I beat its head as hard as I could with my fists and it had zero effect. I am 6’ tall and fairly strong. I lift logs and weights and heavy parts regularly. I am no weakling or slouch. Yet I couldn’t budge this fucking pig off me. He was shaking me so hard I started to black out and I knew it. I started getting tunnel vision and my field of view was pinholes. I was going down and this pig was going to eat me. My only thought was that it was going to eat my wife who would eventually come to the pen to look for me.
I blacked out for probably a few seconds until the pig whipped around and attacked another pig that came over to see what all the noise was about.
I literally crawled out of that pen and my legs didn’t work for a while.
I slept in the mud for an hour until my wife came by and called me lazy slob for laying in the mud. She had no idea.
The bad pig was now calm and even wiggled its tail for her.
I don’t know what the heck got into that pig, but for a few minutes it was a demon.