I don't know if this was evil, but it was definitely outright malicious.

When I was nine, I had a friend named Allison (not her real name). She was a complete cunt, and I hated her even then. I still look back and question why we were friends; I did have other friends.

Anyway, one day I was at Allison's house. I don't remember what happened, but she'd upset me. Then she went into her mom's room to ask her something (her mom was always asleep during the day). I was sitting in the hallway waiting for her to come back, and I happened to notice a needle lying on the carpet. I remembered what a cunt Allison had bee, and I wanted her to step on it.

So I picked it up, and I wedged the butt in the carpet in the center of the doorway, so it was pointing up. This was a long needle, and when Allison came out of the room, she stepped on it, and it went almost completely into her foot. She bled. She screamed. She cried. It was glorious.

Unrelated: Years later, when we were 22ish, Allison was arrested for having sex with two fifteen year old boys at the same time.