While the most famous superheroes are often of the living variety, gaining their powers by cosmic events or freak accidents (along with mere mortals possessing expert skills), the supernatural has also played a major part in the creation of many iconic comic book heroes and villains. The undead are usually depicted as bad guys of course, but there are several notable heroic characters who gained powers by various unsettling means, be it a scientifically reanimated corpse or a supernaturally resurrected spirit, and sometimes even a combination of the two.

With that in mind, here are the 15 best undead superheroes. Note: in an effort to keep this a streamlined list, we had to limit our mentions of DC's Blackest Night or Marvel Zombies. The characters we've assembled here are known best for their undead status, not for being prominent superheroes brought back from the dead (with three notable exceptions, who were just too cool to leave out).

With that out-of-the-way, here are the all-time coolest heroes from beyond the grave.

15. Zombie

Tales of the Zombie Marvel

Long before the days of Marvel Zombies, The House of Ideas created Simon William Garth, a singular zombie who first appeared back in 1953. Garth was an executive in New Orléans, who in a bizarre turn of events was attacked by his former gardener in retaliation for being fired.

Soon, Garth is used in a ritual voodoo sacrifice, resulting in him being placed in a zombified state by the mystical Amulet of Damballah (which he wears around his neck). Initially a mindless savage killing machine, Garth is transformed into a semi-sentient being, able to possess a muted sense of empathy that led to him helping others.

Blessed with super-strength and healing abilities, Zombie is nearly indestructible, his sole weakness being that he can be commandeered by anyone else possessing The Amulet of Damballah. Zombie has gone through various incarnations over the years, and has encountered the likes of Spider-Man, Blade and Deadpool. He remains a unique, singular presence in Marvel Comics, offering one of the earliest infusions of occult mysticism into the company's history.

14. Simon Dark

Simon Dark DC

Batman isn't the lone nocturnal avenger in Gotham City. Simon Dark is an avenger of justice, protecting the residents of the downtrodden neighborhood known as "The Village." Dark is an amnesiac endowed with super-strength, speed, and agility, and he gained these powers through morbid and bizarre means: he's an amalgamation, created from the bodies of 20 young boys by a mad scientist who used occult magic from a villainous sect.

However, Dark wasn't created to serve the dark occult powers that brought him into his world. On the contrary -- he was designed to take them out. This takes time, however; Dark has a slow evolution as a being with only childlike intelligence, who gradually grows into skilled fighter with a variety of macabre abilities like being resistant to bullets, clairvoyant, the ability to change his face, the power to bring back the dead, spell-casting capabilities, and the ability to transport into other dimensions.

Dark is also aided by a group of shapeshifting servants known as The Familiars, who were also liberated from the evil cult he was created to destroy. A weird and eerie presence even by Gotham standards, Dark may not be as revered as The Dark Knight, but he certainly deserves more street cred.

13. Resurrection Man

Resurrection Man on the cover of Resurrection Man Vol 2

Mitchell "Mitch" Shelley is a southern lawyer who gets drafted into a top-secret medical experiment involving nanotechnology (conducted by a shadowy organization called The Lab). This process robs Shelley of his memory for months, but once it returns, he discovers the project has given him everlasting life...but with a catch.

Resurrection Man is one of the more bonkers undead superheroes around. While he's technically immortal, he can still be killed, only to be brought back to life later. And with every rebirth, he's given a new superpower. Sometimes, these new abilities are mind-boggling, like transforming into a gigantic, bullet-proof beast. Other times, his new powers are on the 'meh' side, like changing his skin pigment. They're usually just flat-out odd, though (the ability to conjure fire-blasting butterflies, anyone?).

Despite his novel concept, Resurrection Man has never really taken hold with comic book fans. He's a diamond in the rough, just waiting to be resurrected (sorry) to gain the acclaim he deserves.

12. Ralph and Sue Dibney 

Ralph and Sue Dibney

One of the less-celebrated stretchy superheroes has to be DC's Elongated Man. The character, whose real identity is Ralph Dibny, has the ability to stretch his limbs to great distances.  However, that's not only his only superheroic attribute: he's also one of the all-time great comic book detectives, second only to Batman in the DCU (though The Question certainly gives him a run for his money).

Dibny was aided in his sleuthing business by his wife Sue, who was equally gifted in solving mysteries (the couple were often referred to as "the Nick and Nora Charles of the super-hero set," a reference to the married detective couple of the 1930s and '40s film series, The Thin Man).

The Dibny's rather idyllic life was tragically cut short after Sue was savagely killed by Jean Loring in the 2004 mini-series Identity Crisis. Ralph's grief propels him to find any means necessary to resurrect Sue, but his dabbling in the supernatural ends with him dying as well.

Despite shuffling off this mortal coil, the duo remained active from beyond the grave. They even continued as crime solvers, who turn their deductive reasoning to solving mysteries of the supernatural variety. Eventually, they both were resurrected in The New 52, but their stint as undead sleuths offered a unique take on the characters.

11. Frankencastle

Frankencastle - Facts Punisher

Marvel's The Punisher, aka Vietnam veteran Frank Castle, is a relentless killing machine, waging a relentless war on crime. The character feels timeless, ageless, and despite being merely mortal, almost superhuman.

For a brief period, Castle was actually transformed into supernatural form, after being decapitated by Wolverine's son Daken.  His remains are discovered by Morbius The Living Vampire and the Legion of Monsters, and the group work their undead magic and revive him as an undead Frankenstein-like beast (hence the note-perfect nickname).

Hoping that they could harness Castle's military knowledge to help their cause, Morbius and his Legion are disappointed when he abandons them, remaining his isolationist self. But eventually, after seeing the plight of the group, he agrees to join forces with them while continuing his one-man-crusade against criminals. Castle would eventually be brought back to life in human form, but the Frankencastle arc remains an entertaining, if bizarre, chapter in his storied history.

10. Hannibal King

Marvel Comics Hannibal King

This supernatural sleuth, who originally appeared in 1974's The Tomb of Dracula #25, was cursed to live as a vampire after being attacked by the villainous Deacon Frost. Horrified at his transformation, King vows never to feed on another living soul, instead gaining his sustenance from blood banks, corpses, and animals. In many ways, his actions feel like a denial of his symptoms -- he rarely uses his undead abilities.

But that doesn't mean, he never relies on his impressive supernatural skill-set, which includes immortality, a healing factor, and the power to turn into mist or even a werewolf.

Given his affliction, King's detective duties are only carried out nocturnally, occasionally teaming up with the likes of Blade, Doctor Strange, and Spider-Man. Blade is a recurring character in King's trade, with the duo teaming up on various missions to battle vampires not as heroic as themselves. Eventually, Blade even helps King with his thirst for blood, providing a potion that takes away the urge entirely.

9. Frankenstein

Frankenstein DC

A member of DC Comics' Seven Soldiers, Frankenstein (based on the classic Mary Shelley novel) is a slight departure from the literary and cinematic versions of the beast. Unlike those versions, where Dr. Frankenstein's monstrous creation is eventually killed, he instead travels from Europe to America after being resurrected a second time.

In 2005, Frankenstein is awoken from hibernation to dispatch a race of monsters he had battled two centuries earlier. Despite being a primitive, undead being, Frankenstein leaves Earth to battle his arch-enemy Melmoth on Mars. This climactic battle ends with Mormoth's death, but not before he drops a bombshell on Frankenstein: the creature wasn't reanimated by lighting, but rather by Mormoth's blood, which still courses through his veins.

Despite humanity's rejection, Frankenstein fights for them, facing off against classic DC villains like Darkseid, and eventually joining various super-teams. In addition to Seven Soldiers, he's also provided muscle to groups including Creature Commandos, S.H.A.D.E., and Justice League Dark. He may look horrifying, but he's as heroic as they come.

8. Dead Girl

Dead Girl X-Statix

One of the most bizarre members of (the already bizarre) mutant group X-Statix, Dead Girl (a.k.a., Moonbeam) is a double whammy in undead terms -- she's part zombie and part ghost. This unique beyond-the-grave hybrid had befittingly terminal origins: her mutation wasn't triggered until after death.

Her powers give her the ability to reanimate any appendage that's severed from her body, as well as the power to rebuild her body from the molecular level, no matter how disastrous the damage. She's immune to toxins and can communicate with the dead, either through the spiritual realm or contact with physical remains (even at the bacterial level).

All of these amazing morbid abilities, combined with her heightened physical strength and the power to temporarily resurrect the recently departed, makes Dead Girl one of the most imposing and unstoppable supernatural characters in comics, as well as one of the most powerful merry mutants in Marvel's X-history.

7. Cassidy

Preacher comics Cassidy in front of church windows

A 119-year-old Irish Vampire, Proinsias Cassidy is a depraved immortal who teams up with the super-powered Preacher Jesse Custer. Their mission? To find God and make him answer for the evil sinners that he allows to go unpunished.

To say that Cassidy is a troubled soul is a severe understatement -- a former drug addict who turned to prostitution to feed his habit, his actions have led to the death of several romantic partners. This reckless behavior led a voodoo priest to say "I honestly don't believe he's an evil man. Just careless. And thoughtless. And terribly, terribly weak."

But the wayward bloodsucker begins a slow path to redemption, with his on-again, off-again friendship with Custer allowing brief moments of humanity to emerge between his savage, bloodthirsty ways. Blessed (or cursed) with powerful vampiric abilities and a perverse sense of humor, Cassidy is one of the most unforgettable characters in comics.

6. Deathlok

Marvel Comics Deathlok: The Demolisher

A fatally injured American military officer is resurrected as a cyborg in a post-apocalyptic future. He's a "Deathlok" model, created by the evil Simon Ryker, designed as a super-soldier who verbally communicates with his symbiotic computer (or as he refers to it, "puter").

However, Deathlok has no interest in being a tool of the military industrial complex, and instead turns against them, while battling the corporate interests that have taken over military operations. In this way, he tries desperately to cling onto his humanity, which remains an ever-present issue as he balances the robotic and organic halves of his personality.

The Deathlok mantle has been passed to a variety of characters, from his original identity as Luther Manning, to multiple other incarnations (including an alternate reality Captain America in the pages of X-Factor), but his grizzled appearance and cybernetic abilities have remained mostly the same, with the occasional high-tech upgrade.

A sci-fi/horror hybrid, Deathlok remains a nightmarish version of the future, even if he doesn't feel quite as far-fetched as he did when the character debuted in 1974.

5. The Spectre

DC Comics' Spectre

One of DC Comics' most ruthless and fascinating characters, The Spectre was originally Jim Corrigan, a beat cop who gets murdered by a gang of thugs. When his spirit is denied access to Heaven, Corrigan becomes an omnipotent vigilante who viciously hunts down his murderers, slaughtering them in ghoulish supernatural fashion.

The Spectre continues his war on crime, doling out terminal punishment on anyone he deems a menace to society. Despite his lonely existence, he was eventually drafted into The Justice Society of America, and has gone through periods where he's not quite as bloodthirsty in vengeance, though he eventually returns to his role as the judge, jury, and executioner of the wicked.

The character has also had a variety of human hosts besides Corrigan, including Green Lantern Hal Jordan and slain Gotham City officer Crispin Allen. But no matter the alter-ego, The Spectre's powers have remained consistent: he's able to bend time, space, and matter to his will, all of which supplies the ability to conjure whatever form of retribution he desires.

4. Spawn

Spawn Demonic Look

Lt. Colonel Albert Francis "Al" Simmons' questions his military role after his sordid work in CIA black ops. His concerns become justified when he's murdered by his partner (and friend) Bruce Stinson. Simmons is then transported to Hell for the murders of innocent civilians during his CIA dealings.

Simmons makes a deal with the demon Malebolgia, exchanging his soul in return for the ability to go back to Earth and see his wife Wanda. Simmons later discovers that not only that his wife has remarried, but he has been also transformed into Spawn, a monstrous being with supernatural powers, including immortality, teleportation, shape-shifting, and super-strength (to name but a few).

Spawn isn't the most virtuous hero on this list; he isn't above killing and has occasionally lapsed into evil. In the end, however, he always returns to his antihero ways, saving his furor and unforgiving punishment for the scourge of humanity and various supernatural threats. He protects the most vulnerable among us while nursing a broken heart for his ex-wife. And his living, symbiotic costume is pretty damn awesome, too.

3. Dr. Manhattan

Death and birth of Dr. Manhattan in the Watchmen comic

Dr. Manhattan is one of the most powerful characters in the history of comic books. The Watchmen character has godlike abilities: he can manipulate atoms, teleport, duplicate, while also possessing a genius intellect and the power of precognition. But none of these omnipotent powers occurred until after his original identity, scientist Dr. Jonathan Osterman was vaporized during a lab experiment.

Osterman was involved in a government experiment with intrinsic fields -- the ability to manipulate objects to disintegrate. In a poor stroke of fate, the scientist enters the chamber to recover his coveted keepsake watch. But a safeguard locks the door, and he's completely atomized as result.

Over a series of months, Osterman slowly reconstitutes his form, from a floating nervous system, to the circulatory system, and later a muscled skeleton, before going through his final transformation: a nude, glowing, blue humanoid. Just like a holy resurrection, Manhattan is a mortal who returns with the powers of a deity.

2. The Crow

Brandon Lee in The Crow

Eric Draven's life is ended in brutal fashion after a gang of murderers attack him and his wife Shelly. His death is made even more torturous when his attackers brutally rape and kill his wife Shelly right before his very eyes. His need for vengeance and his overwhelming sense of grief prove too powerful to end, even in death, and he's resurrected a year later by The Crow, a spirit of vengeance that allows the dead to come back and gain the justice they were denied in life.

Draven's rebirth makes him impervious to pain, but perfectly able to dish it out tenfold upon the men that murdered him and his wife, killing them as savagely as he was murdered himself, but in vastly more creative ways. Once his vengeance is carried out, he's finally able to rest in peace.

The Crow has resurrected many other unfortunate souls to enact their own vengeance, in both the film series and a host of comic book series, all of which keep the mystical entity's satisfying brand of undead karma very much alive.

1. Deadman

DC's Deadman showcasing his powers

Boston Brand is a circus performer noted for his trapeze skills and his eerie, corpse-like makeup. But his ghostly visage becomes tragically prophetic after he's murdered by a mysterious villain known as The Hook.

In a stroke of luck (or tragedy, depending on your take), Brand gains mystical powers from the DC Hindu god Rama Kushna to help bring his murderer to justice. Under his new identity as Deadman, he's able to maintain his consciousness while gaining ghostly powers (as well as being undetectable to humans). He's also able to leave his spectral form for brief periods, with the power to posses any living creature to do his bidding.

Brand gained even more powers after he possessed the White Lantern ring (during the events of the Whitest Night miniseries), including the power to bring the dead back to life.

One of the more underrated characters in DC Comics, Deadman has gained new notoriety as a member of the supernatural super-team Justice League Dark. With an upcoming animated and feature film in the works, he may just become a household name yet.

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Which undead superheroes would you add to the list? Be sure to sound off in the comments section. (Feel free to mention your favorite Blackest Night or Marvel Zombie character, too!)