Frank Castle is Marvel's most notorious anti-hero, delivering his own style of brutal vigilante justice since he first blasted his way into the comics in 1974. A man with a grudge and a lot of guns, the ex-Marine began his war on crime following the death of his wife and children, vowing to kill all wrongdoers.

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Although he is full of good intentions to wipe out criminals, his murderous methods are questionable. He has repeatedly clashed with some of Marvel's most noble heroes who disagree with his bloody form of justice. Occasionally, Frank's mission has caused him to teeter over the edge into full-on villainy. Here are some of his most notorious villainous moments ever.

10 10. Zombie Frank

When Ashley J. Williams crashes into Earth-2149 in 2007's "Marvel Zombies vs. The Army of Darkness," he teams up with the Punisher to find the Necronomicon. Frank's guns-blazing approach is his downfall as he mows down humans and zombies alike until he's eventually overrun.

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Frank would later prove to be just as cold in the afterlife. With Ash managing to team up with Scarlet Witch – a powerful magic user who knows a thing or two about changing realities – zombified Frank tracks the heroes down to Doctor Doom's castle in Latveria, fighting Doom before infecting Scarlet Witch, killing the one surviving person who may have been able to cure the outbreak.

9 9. The Punisher in Riverdale

In one of comics' most bizarre crossover events, Riverdale found it had a new, imposing character darkening its doorstep. With a notorious criminal known as Red hiding out in the small town, the government hired the Punisher to track the crook down. Unbeknownst to poor Archie Andrews, the criminal looked just like him and the Punisher remained hot on his heels, leading to all kinds of calamity.

Related: 10 Times Archie Comics Went Crazier Places Than "Riverdale" Has

While the hijinks made for entertaining reading, things escalated when the Punisher held Archie at gunpoint. His grim appearance and threatening attitude made him an awkward addition to Riverdale and the real villain of the story.

8 8. Doctor Punisher

One of the most frightening changes made by the patchwork planet of Battleworld was Frank Castle's brutal code of killing merging with the incredible powers of the Sorcerer Supreme. Instead of following in Doctor Strange's footsteps and using his magical abilities to protect Earth, he turned against his fellow heroes, killing Spider-Man and Ghost Rider before turning the Hulk himself into dust!

This demonstrated just how dangerous Frank's impulsive reactions and remorseless nature could be, when combined with superhuman abilities. No longer limited by the need to take aim or reload, the Soldier Supreme can wipe out anyone he pleases with a simple snap of his fingers.

7 7. Gunning Down Allies

With "Civil War" drastically dividing superhumans across the globe, the entire conflict is a murky grey area, with no one truly in the right or wrong. With losses being felt on both sides, both Iron Man and Captain America were willing to welcome villains into their teams.

Related: 10 of the Most Devastating Wars in Marvel Comics, Ranked

When Goldbug and the Plunderer arrive on Cap's doorstep, Frank automatically followed his own moral code of killing criminals and viciously gunned the pair down before they had the chance to plead their case. As a result, a furious Cap attacked Frank for his lack of restraint, reminding us that the Punisher does not play well with others.

6 6. The End

Following conflict between the U.S. and China, Marvel's universe was plummeted into a post-apocalyptic wasteland. Old Man Castle emerged in this ravished world to hunt down the wealthy elite responsible for the missile launch, who just so happen to be the last remaining people on Earth.

Confronted with the choice of letting them live and help them repopulate their brave new world (with genetic samples they had stored) or kill them all and end the human race for good, Frank characteristically stuck by his moral code and wiped out the would-be overlords in a bloody shooting. By so doing, he destroyed any hope of rekindling life and humankind's future.

5 5. Insanity

Consumed by his mission to wipe out criminals, Frank has long battled with himself. When it appeared that he was finally losing his grip, his friend and ally Microchip locked him in a safe house for his own protection, conducting experiments to try and help him. Frank didn't see this as help, however, but betrayal.

Frank broke out and threatened to kill Micro, only for Stone Cold to arrive and do the job for him. After dispatching Stone Cold, Frank considers his dead friend for a moment before walking away. Apprehended by S.H.I.E.L.D. shortly after, Frank escaped once again, but not before killing a Nick Fury decoy, forcing him to run from the law.

4 4. Battling Wolverine

The Punisher is well-known for fighting against some of Marvel's mightiest heroes, first appearing in Amazing Spider-Man #129, believing old webhead to be a crook. While these confrontations usually end with a beating and the opponents going their separate ways, Frank's fight against Wolverine in 2002's Punisher #17 pushed his boundaries to their limits in a cruel, gruesome conflict.

Related: The Punisher: 5 Heroes Frank Castle Has Beaten (& 5 He Can Never Win Against)

Shooting Wolverine in the face with a shotgun (and ripping the skin clean off) was just the beginning. Punisher then shot Wolverine in the groin, before running him over with a steamroller of all things! Logan might be able to heal himself, but this extreme attack showed Frank at his coldest.

3 3. Hail Hydra

Frank Castle has a lot of respect for Captain America, but his involvement in the controversial "Secret Empire" series baffled many readers. Recruited by the Hydra-serving Steve Rogers to conduct kill missions, Frank became a willing servant to the evil empire, never questioning Rogers' orders. He became so engrossed in it all, he even changed his iconic skull emblem to Hydra's symbol.

His involvement was later revealed to be the result of Hydra's manipulation of Frank's admiration of Steve. However, it's unlikely that a man who abides by such a brutal code against his enemies would have needed much convincing.

2 2. Death to Superhumans

The Punisher really let loose in 1995 mini-series, "The Punisher Kills the Marvel Universe." Arriving in Central Park to discover his family has died, caught in the crossfire between superheroes and alien invaders. Quickly dispatching Cyclops, Hawkeye, and Jubilee, Frank is arrested and sent to prison, but the bars can't hold him. Rescued by a man named Kesselring, Frank vows to kill all superhumans.

In a bloody series, Frank hunts and murders everyone with super-abilities, from Spider-Man, Venom, and the Human Torch to Kingpin, Doctor Doom, and Captain America. He even murders human Bruce Banner in his sleep. It's a chilling series of pure revenge that shows no-one on Punisher's list is safe.

1 1. X-Men on the Moon

While Frank hunting down all of Marvel's superhumans in "The Punisher Kills the Marvel Universe" was cold, his calculated plan to murder Earth's mutants shows how devious he can truly be. Gaining access to Doctor Doom's weaponry, he lures all surviving mutants to the moon's surface, faking a battle. When the heroes and villains realize they've been tricked, it's too late. Frank launches a nuclear missile, wiping them all out.

With Wolverine being the only surviving mutant, Frank violently kills him by piercing Logan's own claws through his chest and throwing him into a generator, overloading him with so much electricity that he's unable to regenerate. Frank's attacks on the superhumans may have been ruthless, but his murdering of mutants is even worse.

Next: 10 Marvel Villains Who Are Beyond Redemption