Lethal Klutz

Some characters are Too Dumb to Live. This guy is too dumb for everyone else around him to live.

This is the guy who, on getting out of bed in the morning, somehow manages to trigger a set of Disaster Dominoes that ends up blowing up his next door neighbor's house. After that, he'll swerve to avoid a squirrel on the commute to work, accidentally running a passing Bus Full of Innocents off a cliff. When he gets there, he'll distractedly fire a nail gun straight into the forehead of the resident Butt Monkey, then, after lunch, flip his Banana Peel onto the floor right in the path of an elderly hemophiliac.

He'll never notice any of this.

And what's that high-pitched screaming coming from under his car on the drive home? Meh. Probably the wind.

The Sadist Show is his natural habitat. He's been known to show up in Crapsack Worlds when they're Played for Laughs. Can lead to Mistaken for Badass when people are impressed with the results of his "work."

This trope is a brutal deconstruction of The Klutz, but unlike most, it's Played for Laughs far more often than for drama.

It's the middle step between The Jinx and Mike Nelson, Destroyer of Worlds. I Just Shot Marvin in the Face is a Sub-Trope. Spanner in the Works, Doom Magnet, and Walking Disaster Area are Sister Tropes.

Anime and Manga

 * Fran of Franken Fran is one of the few non-comedic examples. In fact, she might be the best example of this trope deconstructed. Since this is itself a deconstruction, that's impressive.
 * Excel from Excel Saga. The many ways in which she kills Pedro are particularly notable.
 * Sayonara, Zetsubou-sensei:
 * Chiri tried to be a normal klutz, but ended up this.
 * In one episode, Nozomu is being held captive in a government facility, and his students recognize him, drawing on their respective skills. The Apologizes a Lot girl Kaga bows her head to apologize, and keeps accidentally banging her head into guards. She keeps apologizing every time this happens and as a result, accidentally kills a bunch of people.

Comic Books

 * The title character of Lenore does this quite often.

Live Action TV

 * There was an episode of CSI with this guy. He accidentally killed his wife and somehow decided that the best thing to do was bury her in fresh cement at a construction site... where he got stuck. It got worse when they delved into his backstory. Some characters found his antics funny but Grissom was just disturbed.
 * Scrubs:
 * Doug, one of JD's classmates. They eventually solve this by making him a coroner.
 * JD's girlfriend Julie has classic Klutz tendencies, but when there's someone else for her to hurt she'll find an interesting way to maim them. Elliot was often a victim.

Film

 * Played for Laughs in True Lies, during a scene where Helen accidentally kills a group of terrorists while trying to fire an uzi, to save her husband, Harry. The recoil causes her to lose control and fumble the weapon, sending it tumbling down the stairs in a slow-motion montage sequence where it continues to fire, taking out several Mooks.
 * Seymour in The Little Shop of Horrors (the original movie).
 * In Star Wars: The Phantom Menace, Jar Jar Binks destroys quite a few combat droids accidently during the final battle for Naboo. In one scene he accidently unlatches the door to a stash of grenadelike devices, sending them into the enemy ranks; in another, his foot get caught in one droid, and trying to escape causes the droid's blaster to fire, taking out another droid.
 * Naked Gun 33 1/3: The Final Insult shows that Drebin has accidentally killed his fiancee. He remains unaware of that.
 * To elaborate, he lived on top of a steep cliff, and on their wedding day he slammed the door open just as she was about to enter, throwing her off the edge to be eaten by sharks.
 * In the same movie he is also celebrated for killing a record number of drug dealers. He laughingly confesses that he backed over the last few with his car by accident.

Video Games

 * Aperture Science can't build a calculator without it malfunctioning and killing dozens of test subjects. As Portal 2 explains, their founder built the company from the ground up to have No OSHA Compliance and fired anyone who opposed it. That kind of bit them in the ass later.

Web Original

 * Most characters on Happy Tree Friends, but resident ditz Lumpy takes it Up to Eleven.
 * Salad Fingers
 * Hal the Misinterpretive Porn Star, who on one occasion, manages to launch his co-star into space.
 * Red vs. Blue gives us Caboose, who has a history of team-killing people he tries to help. So much so that, not only does the Blue Team tell Caboose to help someone they want shot, Command has their own keyboard shortcut for his TKs (Control+F+U).

Western Animation

 * In one episode of The Simpsons, Ralph Wiggum runs out into the street directly into the path of an oncoming car. Fortunately, his dad had installed a "security system..." in the form of a spike strip deployed across the road that threw the driver through the windshield and face-first onto the asphalt.
 * Homer - who designed said "security system" - is a great example, too.
 * Dethklok from Metalocalypse. They manage to kill fans at every show, the faulty and badly-conceived products they endorse cause countless deaths, and that's not even getting into the times when either they or their fans have people murdered intentionally.
 * South Park: In a flashback, the last time Butters tap danced in "The Tap Tragedy", he accidentally killed eight people.