Dogs are faithful companions and beloved members of the family, which is why they make the perfect villains. Audiences get to see something as familiar and comforting as a cuddly canine sidekick and it's transformed it into a menacing adversary. This is an effective way for filmmakers to unnerve the audience.

This is a concept that was first unintentionally explored in Old Yeller, which remains the worst movie a child should ever watch. The so-called family film did however show that turning a dog on its master is a solid way to terrify people and, as a result, some of the best movie bad guys are actually evil dogs.

10 Mr. Beefy

Little Nicky

Mr. Beefy from the Adam Sandler movie, Little Nicky, isn't evil in the sense that he slaughters the innocent, but he is literally from Hell, so he counts. Little Nicky is the son of Satan, who is sent to the human world to stop his brothers from creating Hell on Earth.

Nicky is unfortunately a bit naive and timid, so he struggles among the living. Papa Satan sends Mr. Beefy, a talking Bulldog, to help Nicky assimilate. Aside from providing laughs, Mr. Beefy teaches Nicky how to eat fried chicken and ultimately helps him defeat his evil brothers.

9 Zowie

Pet Sematary Two

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The rules for Pet Sematary are simple: bury something in the sour ground, and it will return to life. They however don't come back good as new and in the first film the protagonist couldn't seem to understand this as he buried his cat, his toddler, and his wife, all who returned as zombified killers.

In Pet Sematary Two, Jeff Mathews inters his beloved Husky mix Zowie in the legendary Miꞌkmaq burial ground, and she predictably comes back more aggressive. In reality, Zowie isn't entirely evil, often showing up just in time to rip the villains apart, but she is still undead, which makes her hard to train.

8 Zuul & Vinz

Ghostbusters

In Ghostbusters, Vinz Cloortho is the "Key Master" who possesses Louis Tully, and Zuul is the "Gatekeeper" who takes over Dana Barett. Once together, they open the door to another dimension, allowing Gozer to enter the human realm and attempt to destroy the world with a giant marshmallow man.

It's unclear that Zuul & Vinz are actually dogs, and certainly not any recognizable breeds, but Louis remarks "Nice doggie" when chased down by one of the demigods. Also, in Tobin's Spirit Guide there are illustrations of the two minions of Gozer that are listed as "terror dogs," so they must hail from the canine family.

7 Max

Man’s Best Friend

Max from the 1993 film, Man's Best Friend, is a Tibetan Mastiff that has been genetically altered to be faster and stronger, with heightened senses. He wouldn't be staring in a horror film if he was some kind of super dog, so obviously the experiment didn't go well, and the powerful pup went berserk.

Actually, Max racks up a body count that many human slashers would be jealous of. Having his genes spliced with DNA from big cats, snakes, chameleons, and birds of prey, Max is intelligent enough to know how to cut brake lines on a car. He also urinates acid, capable of burning human skin, so he has many tools of destruction at his disposal.

6 Cujo

Cujo

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The Stephen King adaption, Cujo, did a brilliant job of casting a St. Bernard as the rabid killer dog. It's not a breed associated with aggression, so there is a nice juxtaposition between the perception of it being a friendly dog and the terror it unleashes.

Also, it's big enough to represent a real threat. Nobody wants to get bitten by a rabid Miniature Schnauzer, but it's a survivable attack with proper treatment. A 180-pound St. Bernard with rabies however is capable of tearing a human to shreds.

5 The Grim

Harry Potter and the Prisoner of Azkaban

English folklore has a tradition of mysterious black dogs that are supposedly bad omens. In the Harry Potter books, a black dog known as The Grim, is established as the worst possible omen, bringing death to however sees it. In Harry Potter and the Prisoner of Azkaban, the young wizard spots The Grim coming out of the bushes just as the Knight Bus shows up.

Later, in divination class, Harry gets The Grim in his tea leaves reading. Cleary this wasn't a harbinger of Harry's eminent death and The Grim turned out to be his godfather, Sirius Black, who was trying to protect him. Another piece of English folklore is The Gurt Dog, which is a benevolent black dog that acts a guardian, but that's not nearly as ominous.

4 Racist Dog

White Dog

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Despite staring known actors like Kristy McNichol, Paul Winfield, and Burl Ives, the 1982 film, White Dog is obscure, never having been properly released. Paramount Pictures felt the story of a white German Shepard that had been trained to attack Black people on sight was too controversial and shelved it until 2008 for a DVD release.

Rather than being an exploitation of stereotypes, it's a thought-provoking film that explores the irrational nature of human hatred. The vicious dog is merely a placeholder for the true evil of racism. The theme that racism is learned comes to the conclusion, in the rather upsetting ending, that it however cannot be cured.

3 Zoltan

Hound of Dracula

Make no mistake, Zoltan from the Hound of Dracula, also known as Dracula's Dog, is a vampire, but it's debatable if the Doberman Pinscher is actually evil. Vampires need to feed on blood to live, so it can be argued that they are only trying to survive, which is a natural instinct, not an evil trait.

In the movie, Zoltan is only trying to locate his master, rather than unleashing a campaign of terror and carnage. He does bite a pair of German Shepards and a Pointer, but dogs are pack animals, and who doesn't want friends? Of course being Count Dracula's vampire Doberman, checks off a lot of evil boxes that are hard to ignore.

2 Zombie Dogs

Resident Evil

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Doberman Pinschers were bred aggressive with the specific purpose of being guard dogs. In Resident Evil, The Umbrella Corporation bred them further to be skinless zombie attack dogs, which is as horrifying as it sounds. Even Alice's enhanced abilities are no match for zombie dogs.

Alice is a more-than-capable butt-kicker, but when she encounters the zombie dogs, audiences can feel her sense of terror and helplessness. A product of the "Cerberus Project" these zombie Dobermans were initially developed as a biological weapon, and like every experiment from Umbrella Corp., they proved to be uncontrollable.

1 Satanic Rottweilers

The Omen

Many people fear Rottweilers because they are a muscular breed that look menacing. In reality, dogs are only as good as their owners and most Rotties are sweethearts, known for their calm demeanor and even temperament. They almost certainly got their underserved reputation from the Satanic Rottweilers in 1976 film, The Omen.

Sent straight from Hell to protect the Antichrist child, the Rottweilers are some of the scariest creatures in any horror movie. In Greek mythology, Cerberus is the three-headed dog that guards the gates of Hades, but these Rotts are Hellhounds, which are guardians of evil away from the eternal pit of fire.