Let's call him Jack.
Jack joined the ever-rotating roster of players I had in Middle School.
I DMed for him, I played alongside him, and it was irritating to do both.
See, he had a character die in nearly every single session. And everytime a character died, he'd get mad. But then he'd do something similar that'd get his new character killed in the next game.
It didn't matter if it was D&D, Middle Earth Roleplaying, or Star Wars d6. He would roll up a character, and it'd often be dead in the very same session.
We started calling him "Cannon fodder Jack."
What's even worse that he often refused to look at the rules. He wouldn't pay attention to the game. I let him play because he didn't have too many other friends, and he would almost aways roll up a fighter. The group always seemed to need a fighter in those days.
One of Jack's first characters was a human fighter. It got killed in the Haunted House outside of Saltmarsh. Something about, "don't search the dead body, let's poke it first." But he searched the body, and died of rot grubs.
Next character: A human fighter who wandered away from the group for no apparent reason. He just suddenly announced he was walking away from the group. Killed by a random encounter with orcs or goblins after two days of walking away from the group.
Next character: A Half-Ogre fighter. A real brute. Killed while charging a warband of 30 or so orcs after the group said, "NO! STAY BACK! Let's hit them with missile fire and draw them into an ambush." (I'd even fudged a few die rolls to try to keep the character alive).
Sometimes, however, we'd end up in a game together at somebody else's house, and he would pull the same stupid crap. Once, in MERP, a fellow PC and I actually tied up Jack's hobbit because Jack's hobbit was trying to kill our character. (This was after his last character got surrounded and killed by 10 orcs after we told him to run away, fall back with the rest of the group)
At some point, a mutual friend told me that Jack did not like me at all. He thought I was trying to take the few friends he had away. He thought I was out to get him. Once I asked Jack about this, but he wouldn't say anything. This was before he stole from me.
I should have cut him loose then, if not before. But little did I know I'd fallen into 5 Geek Social Fallacies. But I tolerated him for a couple years because I could count on him showing up to a session.
Jack's next and LAST character: A thief. Killed while climbing the walls inside of a tower, making himself the perfect target for an enemy crossbowman, while the rest of the group engaged in melee combat with the rest of the enemies.
After the session ended, I discovered Jack was a thief in real life; he stole some of my miniatures. The miniatures were on the kitchen table when I went back to my room to put some books away. I overheard Jack say, "Well, I'm gonna go." He was standing next to the kitchen table. When I came back out, Jack was gone and so were the miniatures. I banned him from my home.
And then things went downhill from there. He started prank calling me, or trying to start fights on the bus afterschool. Jack also had a minor role in a mutual friend's D&D stuff getting burned. Jack would rat him out to his parents whenever he found out I running a D&D game at my place.
We got into a lot of fights.
Once, after a game and somebody else's place, he slammed the front door on my nose. I pushed the door back open, punched him in the throat, which sent him backward over a kitchen chair. I stormed home with a bloody nose.
Another time he ran at me, swinging a rusty saw (its a long story as to why he had the saw), so I picked up a large stick and bapped him over the head. He said, "Ow!" And dropped the saw. I dropped the stick and proceeded to beat the crap out of him.
I remember getting in trouble for it, and I'm surprised the police didn't get involved. But once I said, "Jack charged me with a rusty saw," Jack was the one who got in the most trouble, despite me being the one to give him the serious drubbing.
Yeah. Fun times.