A number of characters in Asterix are threatened with things like being roasted alive, crucifixion or (Once An Album) being flung to the lions of the circus. Justified as this is Ancient Rome we're talking about.
And flicking the president of Bialya under the chin hard enough to send him flying into the ceiling with enough force to liquefy his head.
Psycho-Pirate's fate in "Infinite Crisis", where his mask is pushed through the back of his head. "No more silly faces."
In Black Hammer, Colonel Weird's girlfriend is messily torn apart when she tries to enter the Para-Zone with him. Her skin is ripped right off her body and her organs seemingly phase out of her to go drifting off in all directions. Black Hammer dies in the exact same way when he tries to cross the invisible boundary around the Farm, foreshadowing the much later reveal that the Farm is within the Para-Zone.
Crossed is made of this trope. Anyone who falls afoul of the titular psychopathic monsters will die an unthinkably horrible death, usually after being raped and tortured for hours. Some of the non-Crossed characters also prove capable of murdering other survivors in brutally nasty ways.
The Italian horror comic Dylan Dog gets really creative with this trope. Just to list some, Issue #21 has a man being inflated with gas until he explodes like a balloon, Issues #28 and #107 follow a Roger Rabbit expy "Pink Rabbit" who kills people in cartoon gag-inspired ways not too unlike The Mask comic, and both Issues #41 and #73 follow groups of surreal beings driven by Blue-and-Orange Morality that go around killing random citizens in creatively gruesome ways, which include violent mutilations, hanging, decapitation, skinning, melting and disembowelment.
Lots and lots of EC Comics stories (and other pre-Comics Code horror comics, for that matter), often as Karmic Death for good measure. A few unique EC examples being:
Slowly consumed from the inside by fat-eating worms (Vault of Horror #18)
Being compacted into a bone paperweight and flesh spaghetti by an angry, supernaturally shrinking trunk (Tales From The Crypt #38)
Being turned to flesh putty by an alien planet's extreme gravity (Shock Suspenstories #6)
Getting force fed rats, and having your mouth sewn shut as the rats chew through your insides (Vault of Horror #27)
Being stretched out to unnatural lengths on a bed converted to a rack (Haunt Of Fear #18)
Being covered in honey and eaten alive by giant ants ( Crime Suspen Stories #11)
In the ElfQuest: Shards storyline Two-Edge builds a particularly nasty execution device for the human tyrant Grohmul Djun. It consists of two large urns in the shape of birds with upraised beaks, between which the prisoner is strapped. The urns are slowly filled with water, the weight causing them to tip outward, putting greater and greater force on the prisoner's limbs until he is eventually torn in two.
Ch'p, a Green Lantern who looked like a humanoid squirrel, died when he stepped onto a road and was hit by a yellow truck. Just think about that for a second and you'll realize why it qualifies for this trope.
Hack/SlashImplied. We don’t see Lisa Elsten or Chris Krank body’s, due to them being under the covers, but they were killed by Doctor Gross, and there’s copious amounts of blood.
In the Graphic Novel Joker, how did the titular character react to a man insulting his club, eyeing his girl, and then insulting the Clown Prince himself? By skinning him alive.
His Joker Venom, too, considering what it does. First you just start laughing, and you can't stop no matter how hard you try. Then all the muscles in your body begin to seize up, especially in your face, causing you to grin. Then you start to take on the Joker's appearance, white skin, green hair and all. Then the muscle paralysis causes you to stop breathing. THEN you die. Oh, and if you're really 'lucky', he might merely dose you with the non-lethal version, which can cause not only insanity but puts you into a coma...
What he did to Jason Todd in A Death in the Family easily qualifies. He brutally bludgeons him with a crowbar then leaves him and his mother to die in an exploding warehouse.
What he did to Alex Luthor. He ambushed him in a dark alley, sprayed him with acid that wound up melting half his goddamn face off, shocked him with an electric joy-buzzer, and finally shot him dead as Lex insulted him for his myopia and lack of foresight in not allowing the Joker to join the Society in the first place. Oh, and Alex? Deserved it.
The French comic Lanfeust has its share of graphic deaths and bloody scenes, but one of the most cruel and unusual is when Thanos forces Cixi to execute his brother Bascrean by boiling the man's blood inside his body, leaving a charred, messy skeleton behind.
The League of Extraordinary Gentlemen: Griffin, the Invisible Man. He gets beaten, and then raped to death by Mr. Hyde. When he dies he becomes visible, but we only see the contents of one room (and Hyde) covered in blood. Resident Blood Knight Captain Nemo sees what Hyde has done, and is disgusted by it and wants to execute Hyde for his crime.
Powers: Deena Pilgrim gets hits with Cruel and Unusual Deaths when she goes to confront the now-totally-batshit-insane nearly-omnipotent Captain Ersatz of Superman and Captain Marvel called Supershock. First, he strips her naked and flies her into orbit, exposing her to hard vacuum. He then uses his powers to protect her from the vacuum, but kills her with a heart attack. He brings her back to life, then kills her again with another heart attack. He brings her back to life a second time, and kills her with another heart attack. He then brings her back to life a third time, and because he's a sadistic prick, keeps her alive while physically removing her heart from her chest and letting her see him hold it.
The Punisher has his share of brutal kills, but the one that takes the cake is actually his own Rasputinian Death in "The List", he continues trying to stab Daken after — in less than a half hour — having being shot, hit with grenades, punched around, cut across the chest by Daken, broke a leg, getting his throat slashed, lost an arm and about 3 gallons of blood.
Frank himself was probably at his most brutal in the "Slavers" arc in The Punisher MAX. With the Asshole Victims smuggling women into the US to be sex slaves, including an hours-long gang rape on each slave to start out, you don't really feel for them at all when Frank, among other punishments, throws a woman who oversaw this horror into shatterproof glass enough times that finally the frame bends enough for the pane to fall out and she plummets to her death. Or when Frank gets information from a slaver by disemboweling him and hanging his intestines from a tree while still attached. The interrogation is implied to begin at sunrise which makes things worse when Frank casually mentions in the next issue that it took him until NOON to bleed out.
Robin (1993): The Lords of the Avenue are used in an illegal drug trail by Strader Pharmaceuticals, and their bodies start slowly degrading. When Tim finds them in their death throes they look like their veins and skin are melting as they lie helpless and pleading in pools of blood.
To punish Doctor Light, the Spectre transformed him into a candle, with his head as the wick and his body made of wax. The results were obvious after a while. At other times, he transformed a criminal into wood, and chucked him into a grinder. A pedophile was brutally ripped apart by his collection of dolls. He once judged a country guilty (it had a long history of blood feuds and ethnic cleansings). His answer? Burn it to the ground, men, women, and children included, and leave the two top politicians alive, damning them to rule over the devastated land. He even threatened to do the same to the whole of the state of New York (a convicted criminal, who turned out to be innocent, was slated to be executed; this would mean the people of the State of New York would be guilty of homicide by the Spectre's book).
This was always the Spectre's specialty; some classic stories feature, in no particular order: being turned to glass and shattered, being turned into a mannequin and burned alive, melting as if made of wax, drowning in the clutches of a giant octopus; being cut in half by a giant pair of scissors (pictured above), being beheaded by a falling decorative sword, being sliced and diced by a spectral meat cleaver, aging to a pile of dust and simply being reduced to a skeleton in the blink of an eye while being center of attention on a crowded airplane.
This is the modus operandi of Stardust the Super Wizard, a public domain Golden Age superhero, punishing Asshole Victims that deserve it. An example is in punishing a villain who tried to kill everyone in Washington D.C. by depriving them of oxygen, Stardust grew his head until his body was enveloped by it, flew with him very far into space, and threw him in the direction of a headless space giant that envelops heads where its neck should be.
Despite being the first time the topic was ever covered in a mainstream comic (albeit only in a non-canon story), The Death of Superman (1961) features very possibly the cruelest death Superman has ever endured. After being led to believe that Luthor has reformed when Luthor creates the Cure for Cancer, he gets lured into a Death Trap where Luthor hits him with a full-strength Kryptonite ray to weaken him, then straps him to a table and leaves the ray on full blast until Superman finally succumbs to radiation poisoning. There's no noble sacrifice or heroic last stand: Superman, the most powerful and goodhearted hero in the world, dies in immense pain, completely helpless and crying out in agony, while his friends are Forced to Watch. The fact that Luthor clearly enjoyed every moment of it means that when he goes on trial before the people of Kandor and promises to restore their city in exchange for some level of clemency, they throw him into the Phantom Zone without a second thought.
The American superhuman Colossus tries to take on the German "living battleship" Sieglinde when the Nazis attack Paris. Colossus ambushes Sieglinde and at first seems to be winning against her, knocking her to the ground and strangling her... until she rips both of his arms off and uses her matter-disruption powers to twist his entire body into a gory sculpture of pulped flesh and shattered bone. By the end, he's so mutilated it's almost impossible to tell he was once human. The worst thing of all? He's still alive. His skull is so tough it takes five hours for the Allies to euthanize him with an industrial drill.
In another scene, Hitler has another of his "battleships", the Sociopathic Soldier Markus/Siegfried, burn off the face of a disobedient general. The man's death is depicted in loving detail. Similar deaths are suffered by thousands of ordinary soldiers who go up against the battleships.
Siegfried is put down this way in Invasion #7, combined with Death of a Thousand Cuts. It takes the combined efforts of a team of Super-Speed Zephyr Ubers to slit his throat, his disruption halo backfiring on him to blow up half of his face and the subsequent massive blood loss to finally do him in.
The Ultimates: Hurricane is liquefied by Quicksilver.
Overmastery in White Sand. Sand Mastery dehydrates the user, and when you Master too much, magic reaches for all water reserves in your body, quite literally drying you out to death.
Wonder WomanVol 1: Queen Clea loves doling these out, though her attempt to creatively kill Diana and Steve doesn't work out. She has Diana encased in molten metal while Steve is forced into the arena to be eaten by monsters with not but a small sword so that Di will have to hear Steve die as she suffocates. Things go sideways due to Diana being entirely unaffected by the heat and then breaking out of her restraints and Steve being far more competent with a blade than anyone expected.
X23 was bred to be a Tyke Bomb master assassin, and she certainly lives up to her reputation — Captain America spent years personally hunting her down after her first mission. Usually she's quick, clean and efficient. At least until her creator/mother had enough with the abuse the poor child had been subjected to and turned her loose on the project which created her. When X caught up with Zander Rice, the psychopathic lead scientist on one of her main tormentors, she went to work on him for ten minutes. With her bare hands. And damned if he didn't deserve every second.
In Ultimate X Men, a lackey failed Magneto. He was unlucky to have an implanted pacemaker.
And yet again Magneto: In the X-Men graphic novel God Loves, Man Kills, he catches a group of thugs who have just murdered two mutant children. He tells one of the thugs that there is enough iron in an average human being's blood to make a small nail... and then he shows them.
A feat "repeated" by Magneto in X2: X-Men United, the second X-Men movie, with the death of prison guard Mitchell Laurio. Magneto arranged for Mystique to load Laurio's body with extra iron so he'd have enough to escape with.
The mutant-hating Corrupt Church the Church of Humanity captured several young mutants, sometime after the Xavier Institute was closed, including Jubilee, Skin, Magma, Bedlam, and several unnamed victims, crucifying them on the lawn of the mansion simply to Make an Example of Them. (See the Real Life section of this trope for details on this horrid execution method.) Jubilee and Magma survived due to Archangel's healing abilities; the others weren't so lucky.
◊ when the Sentry very literally tears him in half, reducing him to an explosion of bone, blood, and Ludicrous Gibs.
