The undead seems to be a go-to theme in horror films; one which has arguably been overdone to the point of becoming a trope. Yet, amongst the clutter of countless zombie films over the decades, several have withstood the decay of time and have proven bone-chillingly scary to this day. Whether invoked by gory visuals, unsettlingly eerie environments, or tense jump scares - zombie movies have continued to provide thrills and chills.

At the same time, the concept of these staggering, brain-eating beings can also be a funny one, which can serve as comedy film fodder. Various movie creators have caught on to this fact, and have cranked out a number of hilarious features that include them.

Related: George A. Romero's Non-Zombie Movies, Ranked

With that said, let's take a look back into the thrilling history of zombie films and take a look at the 5 scariest - and 5 funniest - movies that feature the undead.

Scariest: 28 Days Later

Cillian Murphy in 28 Days Later

Directed by Academy Award winner Danny Boyle, 28 Days Later utilizes a post-apocalyptic theme which fits the zombie premise like a glove. The cinematography screams "low budget," but this darker, grittier theme in a sense helps establish a more realistic and unsettling atmosphere.

On the one hand, the movie runs with a straight-up thriller vibe chock full of intense action scenes of our protagonists fleeing the undead. On the other hand - it proves distinct in its pioneering the concept of the fast-running zombies, which produces more scares than their slower, clunkier counterparts. It also takes the relatively new Resident Evil approach of attributing its zombie outbreak to a deadly, infectious virus, which has swiftly spread across Great Britain. The speedy, deadly nature of these ravenous zombies, coupled with the vulnerability that the virus brings, makes 28 Days Later one of the most frightening zombie flicks.

Funniest: Dead Alive/Braindead

Before director Peter Jackson was crafting epic, feel-good fantasy films about Hobbits, he was helping to spearhead the idea of comedic zombie movies. These demonstrated that films featuring the undead could be both gory and goofy. Braindead emphasizes a sort of wacky over-the-top characteristic which feels very "British slapstick."

Related: Everything You Need To Know About Dead Island 2

But the film actually contains some impressive special effects, especially given that it's decades old. Rather than run with comedy zingers, this film gets its yuks from the comedically absurd amount of violence and gore. At the same time, the realistic special effects and elements like that creepy, Harryhausen-esque rat-monkey do provide some intense thrills as well.

Scariest: Zombi 2/Zombie Flesh Eaters (1980)

A horde of the undead in Zombie Flesh Eaters

This 1980 classic exists in a convoluted space of similar zombie films - being a "spinoff to a sequel" to the iconic filmmaker, George Romero's Night of the Living Dead. Regardless, this Italian follow-up is very much its own entity in terms of its narrative and gory visuals, and stands out as one of the most thrilling and grotesque films featuring the undead.

Unlike the scientific explanation to the zombie outbreak present in the likes of 28 Days Later, this film plays with the idea of supernatural voodoo-esque sources, making for a creepier, more ominous premise. The secluded environments of the island further add to this eerie sense of helplessness. At the same time, Zombi runs with good old fashioned gross-out moments with its emphasis on realistically gruesome effects and makeup. And how many zombie films can boast an epic showdown between the undead and a shark?

Funniest: Army Of Darkness

Ash in Army of Darkness

Apparently 1992 was the year of slapstick zombie flicks...

While Peter Jackson was going full throttle with the gore-fest that was Braindead, director/writer Sam Raimi dialed back the violence-o-meter somewhat. Instead, he relied on sillier Monty Python-esque scenarios and goofy, quotable zingers for the source of the humor.

The Ray Harryhousen-influenced effects of the skellies contain a gritty, realistic look, while holding an heir of cheap, flimsiness that makes for some visually funny scenes. Army Of Darkness utilizes a spoof-laden, self-aware style of comedy that's reminiscent of Airplane. If the well-crafted action scenes and cool stunt choreography isn't enough to keep you engaged, the funny one-liners like "this is my boomstick!" and "we can take these skeletons - with SCIENCE" certainly will.

Scariest: Train To Busan

A surprise hit from Korean filmmaker Yeon Sang-ho, Train To Busan has just about everything that makes for an enthralling zombie thriller sure to give you goosebumps - superb special effects, creepy jump scares, and gritty-claustrophobia-inducing environments. It also throws large groups of powerful, capable zombies at our protagonists - the likes of which haven't been seen since 28 Days Later.

Related: 10 Deadliest Horror Movie Zombies, Ranked

For what amounts to a basic story of survival as an absentee father tries to get his young daughter to Busan to visit her mother, there's a surprising amount of depth. There's a pummeling of thrilling action intercut with intense, quiet moments to keep you on the edge of your seat. The movie actually gets you invested in its colorful cast of 3-dimensional characters, too. These very human, emotional elements which Train to Buscan nails just add to the tension as we're left to pull for the unlikely survival of our protagonists.

Funniest: Return Of The Living Dead

10 Zombie Movies That Will Make You Die (Laughing)

Dan O'Bannon's Return of the Living Dead (not to be confused with a George Romero sequel of a similar name), rides that tricky line of comedy and horror quite nicely. The movie contains a pretty neat and imaginative governmental conspiracy plotline that sets the stage for a film that's both creepy and amusing.

The fact that these brain-craving zombie can talk, and can take a variety of forms thanks to an outbreak of toxic gas, add a new dimension to the zombie genre and makes for some bouts of tension. At the same time, the absurdity and chaotic nature of film's premise, and its goofy Three Stooges situational humor sets the stage for plenty of chuckle-worthy moments.

Scariest: [•REC]

A woman crawling on the floor in REC

The "found footage" style of filming was, by the mid-2000s, a heavily utilized style of filming which made for a more realistic, and often unsettling atmosphere. While the technique's become a bit overused of late, producing mixed results, the Spanish-made horror film, REC, demonstrates just how well this unique style can compliment zombie films.

After finding herself inside an apartment complex under quarantine, reporter Ángela Vidal is trapped amongst a group of infected inhabitants. The dark enclosure from which the majority of the film takes place creates a feeling of uneasiness and gut-wrenching claustrophobia. This added tension makes the eerie vibe and the zombie jump-scares all the more powerful.

Funniest: Zombieland

There are few comedies - zombie or otherwise - that contain such a robust palette of rich cinematography, a compelling narrative, stellar acting, and hilarious moments like Zombieland. This may be Woody Harrelson as his best - as he manages to create an enduring character despite his comically simple motive to find his precious Twinkie snacks.

Related: 10 Things We Learned From The Zombieland: Double Tap Trailer

Though our co-protagonists, played by Jesse Eisenberg, Emma Stone, and Abigail Breslin have also managed to play roles which are both compelling and believable. This isn't easy to pull off in a film in which countless, ravenous undead roam a post-apocalyptic US. The abundance thrilling action, wacky scenarios, and one of the most amusing cameos of all time help make for a truly unique and charming film. Zombieland stands out as both a powerful zombie thriller and imaginative comedy. Here's hoping the anticipated sequel, Zombieland: Double Tap will live up to its predecessor.

Scariest: Night Of The Living Dead

Night of the Living Dead

While most scary zombie movies rely on jump scares and/or excessive gore to invoke fear - this iconic Romero horror film emphasizes creepy undertones and ambiguity - much of which is "implied" rather than shown. It's not even as "in your face" as the more classically violent '78 sequel, Dawn of the Dead. No, this is the kind of movie you watch in the dark by yourself, and take in the eerie atmosphere that this black and white thriller is so great at creating.

Coming from a pre-internet/cellphone age, Night of the Living Dead does a terrific job of capturing that feeling of desolation and solitude with its vast, empty environments. These feelings only intensify as we see the soulless, dead-eyes undead creeping about. It's the same feeling you might get when walking through a graveyard in the dark, and hearing the ominous hooting of an owl in the distance. It leaves more to the imagination; but oftentimes, our imaginations can paint a scarier picture than a film itself can convey. And it's the reason Night of the Living Dead remains one of the creepiest, most memorable zombie flicks ever.

Funniest: Shaun Of The Dead

Shaun of the Dead Zombies

Edgar Wright and Simon Pegg's Shaun of the Dead seemingly came out of nowhere - during an era when the cultural zombie renaissance hadn't quite kicked in. It reestablished the notion that the undead can be both scary and hilarious, and made a name for itself as one the most unique and memorable comedies of the 2000s.

The film stand outs with a number of distinct, compelling elements. These include cheeky self-aware zombie references and spoofs, funny one-liners, and editing that's both fast-paced and jarring in style. In one sense, the film is unapologetically goofy and slapsticky. These traits are exemplified by scenes like Shaun bashing the heads of zombies with a Cricket bat and feebly tossing discarded records at them. At the same time, there's a surprising level of depth and cleverness throughout that keeps you engaged.

Next: 10 Best Zombie Movies Of All Time