When it comes to horror movies the thing that threatens the characters can really be anything. It could be a supernatural force, a being from another world, or in most cases, another human being. However, when the killer is an animal, it sometimes makes it all the more disturbing. More often than not these vicious animals cannot be reasoned with and only want to kill whoever they come across. That makes them ideal horror movie monsters.

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A horror movie animal's effectiveness often depends on the chosen creature. It can sometimes be an animal people have an automatic aversion to. It can also be a seemingly innocent animal that is used in a clever and unsettling way. Here are some of the best and creepiest horror movie animals ever.

Dog (Cujo)

Cujo from Cujo

Dogs are often called man's best friend, but this pup makes us rethink that relationship. Based on the Stephen King novel, Cujo follows a friendly-looking Saint Bernard who gets rabies and stops being man's best friend. The film has a tense, claustrophobic feel as much of it centers on a woman and her young son who are trapped in their car as the rabid dogs tries to get at them.

Before being infected, Cujo is just another adorable good boy, but when he turns into a slobbery animal, it's enough to turn someone into an instant cat person.

Giant Ape (King Kong)

King Kong remains one of the most ground-breaking films of all-time and introduced one of cinema's most famous and complex villains. Centering around an expedition to the mysterious Skull Island, the explorers soon learn the island is home to a number of strange creatures, primarily a giant ape king called Kong.

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To be fair, any animal the size of King Kong would be frightening. For some reason, the fact that Kong is an ape makes him even creepier. The stop-motion design of the character is amazing for its time and helps make Kong a true monster. However, given his rather sympathetic ending, he doesn't rank among the creepiest.

Rats (Willard)

Willard Ben Crispin Glover

Rats are the kind of animals that naturally make your skin crawl. So the idea of an army of rats all willing to do the bidding of a psycho is the kind of thing nightmares are made of. This effectively creepy tale was brought to the big screen in both a 1971 film and its 2003 remake.

The film revolves around an outcast who uses his strange connection with rats to seek revenge on those who have wronged him. Just the sight of an army of rats can be enough to turn your stomach, but then you can to see what they're capable of if enough of them get together.

Ants (Them!)

Ants from Them

Them! was a science fiction horror film from 1954 that played on the fear of nuclear weapons that existed at the time. The movie centers around a community that is attacked by gigantic killer ants that are the result of nearby atomic bomb testing.

The idea that human impulse helped create these monsters is an interesting concept that is often explored in these kinds of movies. The giant ant designs are effective for the time period and help sell the movie as a fun and creepy B-movie classic.

Crocodile (Rogue)

australian

Rogue is an underrated and little-seen Australian gem of a horror film. The simple story follows a river tour group in the outback of Australia who get stranded on a small rock island after being attacked by a territorial crocodile. The danger mounts as the tides begin to rise, putting the group in danger of becoming a buffet.

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The modestly budgeted film uses its small scale to its own advantage by having the crocodile mostly remain a lurking threat underneath the water. The film maintains the tension throughout and features some nail-biting scenes of the giant beast's wrath.

Wolves (The Grey)

Though it was marketed as a movie about Liam Neeson fighting wolves, The Grey is a much more thoughtful and brutal survival story. It follows a group of survivors from a plane crash stranded in some frozen wilderness. As they desperately try to make their way towards civilization, they are hunted by a pack of wolves.

The wolves are surprisingly seen only sparingly which makes their vicious attacks all the more unsettling. They come across as relentless and sign-minded killer who only care about killing the prey who have wondered in their home.

Spider (Arachnophobia)

The much-shared and entirely relatable fear of spiders in where Arachnophobia gets its title from. The entire movie embraces the fact that people are terrified of spiders and it gives them even more reason to be. The movie centers on a massive and deadly spider who is accidentally transported from the jungles to a small American town where it quickly reproduces and wreaks havoc.

The film takes a lot of joy in making the viewers squirm with plenty of eight-legged creatures scurrying about. Along with the spider-themed horror, the movie also has a fun sense of humor that makes it a real winner.

Piranhas (Piranha 3D)

Most people considered the idea of remaking Piranha, a creature B-movie from 1978, to be a rather silly idea. As it turns out, the filmmakers embrace that idea, making it one of the better modern B-movies. The result is a fun and appropriately scary blast.

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The set-up for the film has a swarm of prehistoric piranha's released from beneath the sea to terrorize a small beach community during spring break. Despite their small size, the creepy fish attack in packs and are quite - um - ugly.

Birds (The Birds)

Tippi Hedren in The Birds

Alfred Hitchcock is a master of suspense. He has a unique ability to draw tension from almost any situation. However, his ability to make everyday birds frightening was a feat even for him. The movie is set in a small seaside town where birds suddenly begin attacking humans.

Birds are never the most intimidating of animals but Hitchcock manages to show that they could be really threatening if the need arose. Part of what makes the movie so unsettling is that no explanation is ever given as to why the feathered creatures suddenly turned murderous.

Great White Shark (Jaws)

Jaws - Bigger Boat Scene

Along with helping to create the idea of the summer blockbuster and kickstarting Steven Spielberg’s career, Jaws also made an entire generation of moviegoers second guess their next trip to the beach. The movie about a killer shark terrorizing a beach community is considered one of the greatest movies of all time and for good reason.

Along with the signature Spielberg heart, the movie is a perfect and tense summer adventure. Much has been said about the difficult production and how those struggles ultimately made the movie better. The music, the fin gliding across the water, the victims being pulled underneath the waves all contributed to one of the greatest movie villain ever.

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