Killer Teddy Bear

A teddy bear, or any other cute plush animal from your childhood just earned a place in your worst nightmares by killing/being used to kill people. Sometimes caused by a Sealed Evil in A Teddy Bear.

Related to Creepy Doll. Sister Trope to Perverse Puppet and Demonic Dummy. Not always a case of Fluffy the Terrible. See also: Everything Is Worse With Bears, even if the plush is not always a bear.

Anime & Manga

 * Kumacy, Perona's personal zombie teddy bear from One Piece.
 * Bleach:
 * Averted with Kon. He may seems creepy at first, but poor guy is totally harmless.
 * This is played with during the Fullbring training of Ichigo: Riruka shuts him in her doll house and his "opponent" is a Yakuza boss trapped in a stuffed pig.
 * There's a scene in Tenchi Muyo 2: The Daughter of Darkness where Tenchi and Ryoko are pulled into Yuzuha's realm and dumped into a toy room. There, they're greeted by a killer cadre of, you guessed it, toys: including a psychotic teddy bear! They soon dispense with the pleasantries, and unleash a rapid fire barrage of knives!
 * Dirty Pair Flash: Murderous Monica, aka "The Pink Sniper", is a teen assassin with a stuffed teddy bear named Mr. Mackie. She uses it as a portable weapons cache, which includes everything from her hair dryer to a laser gun, hand grenades, and an acidic bubble blower among other things. When enraged, she can even transform it into a Humongous Mecha, complete with gattling guns and missle launcher, and pilot it!!
 * The psychic children in Akira first attack Tetsuo after forming a giant teddy bear and other toys out of debris. It's a lot creepier than it sounds.
 * The Ankle Biters from Medabots use a teddy Medabot appropriately called Churlybear. Churlybear looks harmless enough until its owners are provoked into Robattle, at which point its eyes light up with sinister red... and much asskicking ensues. The Medabot can use several extremely powerful explosive blasts, but its signature move is a gravity beam that can completely negate an opponent's speed and agility while throwing it around like a helpless doll - if this attack hits, the battle is pretty much over (Unless, like Spyke, you get extremely lucky...)
 * WaruMonzaemon (and regular Monzaemon, when he's somehow turned evil) in the Digimon franchise.

Comics

 * There's a Buffy the Vampire Slayer comic with some kind of possessed stuffed bear that was used in an attempt to get at Dawn.
 * After his first defeat, Ashley Guthrie from Hack Slash became trapped in his old teddy bear. He didn't enjoy it.

Film

 * Lotso from Toy Story 3 is more indifferent than truly evil.
 * Screamers. Killer robots looking like little girls, carrying killer robot teddy bears.
 * Screamers. Killer robots looking like little girls, carrying killer robot teddy bears.

Literature

 * The Free Kingdomers in the Alcatraz Series disguise their grenades as teddy bears, the logic being that the enemy shouldn't know to run away from their weapons.
 * In Mercedes Lackey's short story The Last Of The Season, a little girl's teddy bear comes to life to protect her from a serial rapist/murderer, which it does with extreme prejudice.

Live Action TV

 * The episode "Ursa Minor" from Tales From the Darkside.
 * Inversion: In an episode of Supernatural with a wishing well, a little girl wishes her teddy bear to life; it becomes suicidal. It eats its gun, but it doesn't work.
 * Saturday Night Live - on the "Consumer Probe" talk show, sleazy toy manufacturer Irwin Mainway doesn't see the harm in his "Teddy Chainsaw Bear".

Video Games

 * Naughty Bear: The whole game is based around a bullied teddy bear in a city full of others teddy bears. And he decided to make them pay. Hard.
 * League of Legends: Annie's teddy bear Tibbers. He's a real grizzly, turned into a teddy bear, turned into a burning abomination.
 * Silent Hill. Some of the enemies you encounter in the altered world are Furry Bunnies. OHGODWHY.
 * In the Hunter: The Reckoning video game, Kaylie's teddy bear becomes possessed by evil spirits and grows to gigantic size before killing her parents, leading to a boss fight.
 * Maple Story Ludibrium is full of these.
 * In Final Fantasy X, Lulu uses her dolls as a focus for her magic, or to act on its own and attack. No one knows how she does this.
 * Guilty Gear: Bridget has several attacks which involve the use of his teddy bear, as well as his yo-yo. One attack has it drift toward the opponent with spinning blades, and another has it grow to gargantuan size and run the opponent over on a flaming tricycle.
 * Carn Evil: Deady, a giant teddy bear boss.
 * In Persona 4 Teddy looks like a teddy bear, but is a deadly fighter with his claws.
 * In The Sims 3, that's probably Dexter The Bear, a stuffed Bear that gives you the ability to kill other sims with either a knife, a poker, or a hammer. The hammer lets you kill toddlers too, which gives way to the creepy toddler behaviors. That is, when Dexter worked properly and didn't crash the game.
 * The Tediz in Conkers Bad Fur Day are an army of these, built by Professor Von Kripplespac with an intention to Take Over the World.
 * Shiki Misake of The World Ends With You once hand-sewed a stuffed cat and named it Mr. Mew. It serves as her sole means of attack in the Reapers' Game.

Western Animation

 * Code Lyoko: The first episode has XANA taking over a teddy bear to become this.
 * On Fairly Oddparents, Timmy's dad sells sock monkeys to Timmy's enemies. When his enemies try to chase him, he wishes the sock monkeys could fight.

Web Comics

 * Reynardine of Gunnerkrigg Court is trapped in a stuffed wolf, and under Antimony's control, but can transform into a life-sized and quite menacing wolf when he feels the need. And he's stuffed full of lockpicks he likes to use like sharp implements.
 * In Sparkling Generation Valkyrie Yuuki, Loki is able to possess a particular stuffed doll, which limits his powers to some extent. But he's almost never seen without a knife.

Web Original

 * He didn't kill anybody as far as we know, but Pedobear probably raped your childhood even more than all the other examples.
 * SCP Foundation: SCP-1048, the cute teddy bear who makes new teddy bears, from things like human ears and aborted babies.
 * The Nostalgia Critic once had to deal with a psychopathic Teddy Ruxpin doll that wasn't very happy about being criticised.