The next one was when I was 14. My friend owns a farm with a bunch of animals, so me, him and 2 others decided we would go camping in the woods for the night. We wanted to make the experience authentic so we brought one of the pigs and then killed it with sledgehammers. We originally had planned on cooking its meat over a fire but we didn't know how to do it so we just left the bloody pig there. My friends dad laughed when we told him about it.
Also in my teen years I used to put mouse traps outside and put bird food on the mouse traps so the birds would walk in it. It never killed the bird, just broke its leg and made it unable to fly. Then I would take the birds inside and put them in a cage and feed them to my dogs.
And when I was 19 I was feeding horses at another friends farm. I was simply feeding them grass, then one of them, all of a sudden decides to charge at me and bites me in the neck. It nearly ripped my neck open and killed me. I told my dad and the next day I got to shoot the horse.
And I've also executed animals like cows and chickens but only for the purpose of giving their meat to the meat industry or because they were going to die anyways.