The Fantastic Four vs. The X-Men limited series is a perfect example. Though the first issue's cover matches a dream sequence, issue 2's cover shows Mr. Fantastic murdered by Wolverine (not in the story), issue 3's cover shows X-Men attacking the FF while wearing Doom's masks (never happens) and issue 4's cover shows the X-Men impaled corpses, the FF rising like zombies and Dr. Doom cowering in fear or Franklin Richards (as you might have guessed, nothing even remotely close happens in this issue). Wanna know the most baffling part? The covers were drawn by the same people who did the interior art!
The Emma Frost series was a cute teen drama about a younger version of the title character pitched at a mostly female demographic. This was undermined because the covers were pieces of absurd fanservice featuring the adult Emma in her New X-Mencostume◊. (Warning, NSFW.)
The cover of Red Lanterns #29, set in the Red Daughter of Krypton crossover, features Supergirl burning her old costume while Superman tries to stop her and Guy Gardner holds him back. Nothing like that happens in the comic: Kara never tries to destroy her Supergirl costume, and Guy actually tries to talk her into staying with her cousin.
Check out Superdickery.com for dozens of examples of dishonest Superman (and other) covers.
A late 80s issue of Superman lampshaded this with Mr. Mxyzptlk indicating that the cover, a giant-sized Superman destroying skyscrapers, probably wouldn't actually happen. In fact, Superman doesn't actually appear within the issue at all — the story takes place during Superman's self-imposed exile into space for killing the pocket dimension version of General Zod and his followers, and the issue's plot centers around Mr. Mxyzptlk returning to Metropolis and challenging Lex Luthor to stop his mischief.
Something of a running gag among comics fans is how many covers Wolverine has appeared on for comics in which he wasn't even mentioned secondhand.
The trope was acknowledged in the nostalgic comic-oriented novel The Amazing Adventures of Kavalier & Clay, when a character finds the latest issue of The Escapist has a cover in which the eponymous hero is being executed by his own alter ego; the character is mildly intrigued but knows that the event will likely turn out to be a dream or an alternate reality or some other cheap trick, if it in fact appears in the issue at all. That may have been directly inspired by the Silver Age Superman cover that had Superman stand around mocking Clark Kent as Kent got beaten up. As it turned out, this was just a metaphor for the fact that Kent had given up being Superman.
This trope is so well known among readers that when an Avengers Spotlight cover showed Hawkeye being shot, Marvel felt the need to put a caption on the cover saying that it was not a hoax or an impostor wearing Hawkeye's costume.
The cover of Amazing Spider-Man #75 is "Death Without Warning" and shows Spider-Man mourning over a dead body. Nothing like that happens in the comic. What's more nobody in the story dies at all. Although to be fair, one villain does get de-aged seemingly into nothingness, so it did appear that he was dead.
The very first issue of Captain America Comics shows CA punching out Adolf Hitler. Hitler doesn't appear in the comic (although various other Nazis do, including the Red Skull).
The cover of Captain America #184 has Falcon holding back Steve Rogers/Nomad so a new Captain America can fight the Serpent Squad. Nothing remotely like this happens in the comic: Nomad defeats the Serpent Squad without any involvement from the others, and Falcon spends the issue trying to dissuade the new Captain America (Roscoe) from taking on the role.
In the DuckTales comics, the cover of issue #15 depicts the Beagle Boys using shovels (or a spoon, in Burger's case) to dig their way under the Money Bin, but in the actual story, they're using a digging machine they stole from Gyro.
The cover of Uncanny X-Men #244 showed Dazzler, Psylocke, Rogue, and Storm cowering in terror from a foe they called "the M-Squad". In the actual story, the M-Squad was a bunch of complete losers who fancied themselves mutant hunters, who the X-Ladies came across trying to apprehend a young mutant while they were shopping at a mall; the heroines pretty much trounced them good. (The cover was likely a joke.) Still, the issue was rather significant due to who the "young mutant" in question was; Jubilee, making her debut in this issue.
Archie Comics usually just display a single gag panel which has nothing to do with any of the stories within. A glaring example of this trope, however, is one for the Betty and Veronica Double Digest issue 128. On the cover, there is a picture of a phone being held by one of the girls, and you can see an image of Archie and Cheryl Blossom in the same image. There's a subtext on the side of this cover that says "Cheryl's back... look out 4 Trbl!" implying that this is the opening story. Not one single story in that book contains anything regarding Cheryl.
Sensational She-Hulk of the made light of cover images that do not refer to the story. Issue number 4 of the same series lampshaded the practice with the comment "Warning the surgeon general has determined that this scene does not occur in the story." The scene showed She hulk in a fun house mirror setting asking when her "golden age guest star would arrive." The Blond Phantom is scene in a mirror pointing a gun at her. The use of fun house mirrors was intended to as reference to the character now looking fat (she had not been a regular character in a comic book for years and had been aging like a normal person). The character does not appear in costume except in flash backs, so there was She Hulk meets the blonde phantom moment in the story, and the cover dramatized the event. Readers at the time must have realized that She Hulk covers did not show scenes from the story, after reading a few issues.
The Marvel issue of "What If?..." that dealt with the Fallen Son storyline had a cover of Captain America carrying an apparently dead Iron Man in a dramatically mourning way. The contents of the comic... weren't nearly so touching.
Many issues of What If...? have covers that pose more dramatic questions than the ones actually addressed in the issue, and often emphasize fairly minor parts of the story. Take, for instance, vol. 2 #5, "What If The Vision had Destroyed the Avengers?" The Vision's role in the story is rather limited — while he is a murderous bad guy, he only shows up near the end, and he doesn't do anything that can be described as "destroying the Avengers." The issue is really about what would have happened if Wonder Man had survived his first encounter with the team.
Vol. 1 #39, "What If Thor battled Conan?" is the question asked on the cover, which depicts Thor and Conan in aggressive stances with weapons raised at each other. Inside, the title page instead asks "What if Thor of Asgard had met Conan the Barbarian?", and the two fight only briefly before becoming the best of friends.
The cover of What if: Avengers vs. X-Men #2 features Thor, Vision, Nova, Ms. Marvel, and Black Panther becoming an alternate variation of the Phoenix 5. In the actual comic, the Phoenix force attacks Thor, and only possesses Nova, Ms. Marvel, and Vision for a few seconds before abandoning them to turn Hope Summers into the Dark Phoenix.
The cover to Avengers Assemble #7 shows Thanos wearing the Infinity Gauntlet and sporting an evil smirk. Not only does this never happen, but the Infinity Gems and Gauntlet never even appear in the storyline (though the Gems are at least mentioned). The actual MacGuffin Thanos is after is the Cosmic Cube.
The cover of one old Star Trek: The Next Generation comic shows Captain Picard floating around in a space suit with half of his face covered in green slime and Counselor Troi looking-on in horror and disgust. Nothing even remotely similar happens at any point in the issue; no space suits, no green slime, and Counselor Troi is barely even featured.
The fourth and final issue of Darth Maul: Son of Dathomir features a cover image that includes Darth Maul wielding what appears to be a variation on a double-bladed lightsaber powered by Mother Talzin's spirit ichor (much like Talzin's own single-bladed pseudo-saber from The Clone Wars episode The Disappeared, Part 2), while assisting Talzin in force-lightning-to-force-lightning combat against Darth Sidious. While the lightning-to-lightning battle aspect depicted on the cover occurs, and Maul does indeed assist Talzin in the battle, at no point does he employ said lightsaber to do so (nor does the lightsaber ever make an appearance).
Most World War II era Marvel Comics have Captain America, Human Torch, and Sub-Mariner having epic battles against the Axis on the cover. The stories themselves though have none of those and are usually about Those Wacky Nazis having their plans for world domination foiled by the heroes.
Malibu Comics used to have a major villain named Rafferty, whose gimmick was that he came with an editorial promise: every time he appeared, a superhero would die! This led to a slew of issues featuring him, many of which showed him threatening a major character on the cover. Too bad those were hardly ever the characters he actually killed. In fact, in most cases he just killed a random walk-on character who had been created just so Rafferty could off him.
Atomic Comics quickly grew guilty of this. While Madman comics had started out having actual, if bizarre superheroic adventures, his latest series, Atomic Comics was much more philosophical than anything else. However, from looking at most of the covers, you would not know this. For example, one cover had two girls, his girlfriend Joe and his friend Luna, who had been fused into the same body in-comic, fighting over him and trying to pull him away from the other, much to his dismay. In the actual comic, the two are complete at peace with each other, only Joe has feelings for Madman, and in fact, the issue isn't even centred around this.
Issue #238 depicted Sonic fighting Mecha Sally, Tails whipping Drago, and Amy about to cave Eggman's face in with her hammer. In actuality, Tails is the one who fights Sally (briefly), Drago is beaten into submission by some wolves, and Eggman doesn't even enter the battlefield.
Amy is featured solo on #240's cover, yet she only appears on the first page. Wouldn't it have made more sense to feature Rotor and Silver instead, since they actually have major roles here?
Further back, #175 showed Eggman holding Sonic in chains, even though Sonic is actually one of the few to escape the destruction of Knothole and imprisonment in the egg grapes.
#225 features the entire Freedom Fighter group, even though only Sonic and Sally have anything more than a cameo within the issue. Most egregious is Rotor, who is given a prominent position on the cover despite not appearing in the issue at all.
All three of the Freedom Fighter teams are crammed together for a group shot on #241's cover, implying some kind of massive team-up. Too bad - the issue is actually about Naugus and Geoffrey arguing over politics and morality, while Sonic and Rotor's teams make pointless cameos. (Silver's team doesn't appear at all. Go figure.)
The main cover Sonic Universe issue 56 features Amy Rose, Blaze The Cat, Marine The Raccoon, Cream The Rabbit and Cheese is a boiling hot cauldron being cooked for Captain Metal's pleasure but in the comic it self that does not happen.
The main cover of Sonic Universe issue 57 features Amy Rose, Blaze The Cat, Marine The Raccoon, Cream The Rabbit, Cheese, Bean and Bark fighting over the Red Soul Emerald underwater while a giant squid attacks them. The giant squid attacks the characters towards the end of the issue but the fighting underwater part does not happen inside The Comic Book itself at all.
The solicited cover for The Avengers (vol. 4) #19 showed The Vision from Young Avengers as part of the new team that was being assembled in the wake of Fear Itself. When the actual issue itself dropped, the cover had been changed to show the original Vision in place of his successor. The ruse was meant to both hide the fact that Brian Bendis was resurrecting the original Vision in that issue, and that the teen Vision was slated to be killed off in the finale of The Children's Crusade.
The last issue of the old Chip 'n Dale Rescue Rangers comic book has a cover depicting Chip, Dale, and Monterey Jack fencing with a one-eyed mouse who has apparently taken Gadget hostage, and it is given the caption "His name is Ransom - and he means trouble!" Not only does this scene never happen in the issue itself, but Ransom isn't even a bad guy.
The Muppet Show Comic Book: The Treasure of Peg-Leg Wilson has two. The most egregious since it's used for the cover of the TPB is Peg-Leg Wilson in a ghost-like form laughing maniacally while the cast looks on in shock and horror, seeming to imply the story arc is some sort of ghost haunting. Peg-Leg Wilson appears on one page in that issue, and it's just a visual narration since Gonzo is reading about his history. Another cover has Kermit and Kismet the Toad in a face-to-face confrontation. Turns out Kermit hired Kismet for a closing act intended to feature Kermit lookalikes (most of which never showed up), and has absolutely no reason to be mad at him at any point in the series. The weirdest part of these examples is that the writer/artist of the series also does the cover art.
The cover for the JLA story Justice For All depicts Superman and Captain Marvel fighting while the Justice League and Justice Society look on in horror. In the story itself, the two heroes' "fight" consists of Marvel knocking out Superman with two punches to prevent him from following Marvel into the 5th dimension.
The cover for JLA: Year One #5 showed the Justice League fighting the Doom Patrol. The reader assumes it's a typical Let's You and Him Fight situation given that it's early in everyone's history and they might not know the others are heroes. But inside the issue, everyone knows who everyone else is and they immediately team up against the real menace.
Issue 9 of the post-RebirthGreen Lantern series features Hal Jordan and Batman in the middle of a fight with each other. It's true that Batman does punch Hal in the issue...as a lighthearted revenge for something that happened in an earlier issue. Most of the issue is the exact opposite of the cover, featuring Hal and Batman becoming friends again.
Sal Buscema was fond of this when he was the artist for Spectacular Spider-Man. Once issue had the Rhino squeezing the life out of Spider-Man on the cover with a blurb indicating that Peter was gonna receive A Fate Worse Than Death. In the issue, Spider-Man is infuriated due to the machinations of Harry Osborn, the second Green Goblin and ends up giving Rhino a No-Holds-Barred Beatdown that leaves the villain crying for mercy. Another issue a couple years later show the Green Goblin gloating over the bodies of Spider-Man and the X-Men. While the X-Men did appear in that issue (it was the final chapter of a three-part storyarc about something different), they never fight the Green Goblin. Instead, Harry Osborn simply returns toward the end of the issue, setting the stage for the next arc.
One Spider-Man cover seemed to pull a subversion on itself. The cover had Hydro-Man declaring victory over Spider-Man, but with Venom's face in the corner, grinning, and saying, "Yeah, right!" making it look like the cover was a joke (and that Venom was actually the focus of the story). The truth is, there was a fight with Hydro-Man in the story, Venom did escape from the Vault, but both had little to do with the actual plot, which was a poignant story of character development for Aunt May's beau Nathan Lubensky, who's gambling addiction had gotten him in trouble with some loan sharks. (This addiction turned out to be a Foreshadowing of what would eventually lead to his death at the hands of the Vulture, sadly.)
In the six-part Spider-Man story "The Assassin Nation Plot", one issue had a cover showing Spidey confronting Sabretooth. Sabretooth did appear in the story, but he and Spidey never met; Captain America and Silver Sable fought the villain, while Spidey was hundreds of miles away fighting terrorists. (Word of God claims that Todd McFarlane penciled the cover before the script was finalized, and while he knew Sabretooth would appear, he didn't know in what regard. The cover was kept because the editors liked it so much.)
Similar to the above example with Sabretooth: Web of Spider-Man Annual #4 showed Spidey about to throw down with the huge, looming, menacing form of the Miami drug czar called the Slug. First of all, the Slug was at most a background figure in the story, appearing in only two brief scenes; Spidey never crossed paths with him, and while he did tangle with a few Mooks who worked for him, the true threat in the story were the minions of the High Evolutionary (the story being a tie-in to The Evolutionary War crossover). And the Slug could hardly have been a threat to any superhero in a physical confrontation anyway (he’s so obese, he can’t even move, needing a mechanical wheelchair to do so).
The last chapter of Spider-Man: Quality of Life, featured the snake-like assassin Yith grinning evilly as she strangled Spidey with her tail. Yith had never expressed a desire or need to kill Spidey during the entire storyline (she wasn't the main antagonist at all having been hired by a Corrupt Corporate Executive to kill Curt Connors) and had been a reluctant ally occasionally. In this part, she turned against her employer, killing him and sparing Connors after falling in love with him. (Probably.)
One Sonic the Comic cover prominently featured Sonic's long-lost brother Tonic standing alongside Amy Rose. In the comic, Amy and Tonic barely interact, and "Tonic" is exposed as Metamorphia (again) within a few pages.
Another cover shows Knuckles and Shortfuse charging into battle with each other. The actual "fight" consists of two blows and the misunderstanding that led to it is quickly cleared up. (As this was a one-shot, there wasn't much time for anything else.)
Both the cover and teaser to Issue 178 proclaim "KNUCKLES VS. CHAOS!!!" With Knuckles and Chaos squaring off. In the actual issue Knuckles jumps to fight Chaos but is instantly crippled by Chaos's fear ability and is left like that for the rest of the issue.
A terrible habit Marvel is getting into these days is releasing variant covers for their comics to promote films. For example, around the time of the movie, many comics started getting variant covers with The Mighty Thor or his supporting cast doing something completely unrelated to the issue. Made funnier (and more obvious) with any covers involving Loki, since he was about 10-13 years old physically (it's Depending on the Artist) during the time the initial movies were coming out. You saw a grown-up Tom Hiddleston Loki on the cover? It has nothing to do with the story.
The covers to Batman and Robin 23-25 all show Jason Todd in the Red Hood costume he wore during Grant Morrison's run. The problem however is that Jason never wears it, in fact he dons a new costume at the end of the second issue. Which makes the third cover◊ seem like a Take That! in hindsight.
Fans of comic book bondage refer to these as "'gotcha' covers" because they display a woman Bound and Gagged or in some other type of peril that doesn't appear in the comic itself.
The cover of the first Impossible Man Summer Vacation Spectacular (from 1990) shows Impy sunning himself on the beach with almost every major hero in Marvel buried to the neck in the sand around him, with Doctor Doom looming over him. Impy quips, "Like I told these other bozos, quit blocking my sun!" implying he had beaten up the other heroes. It was done for laughs, of course, but there was nothing similar inside the comic. (Which was many different stories about him playing pranks on various Marvel characters.)
Sometimes covers for "big" story lines tend to exaggerate just how many people are involved. Such as in the book "Batman: Battle for the Cowl", it showed characters such as Batwoman on the cover even though she was neither seen or mentioned at all in the storyline.
A common trick in superhero comics is for the cover to feature the villain(s) standing on top of the hero's dead or unconscious body. This rarely happens within the book itself, or if it does, the hero recovers and beats the villain down anyway.
The cover of Victorian Undead: Sherlock Holmes vs. Zombies depicts Holmes as a zombie smoking his pipe. He is never turned into a zombie at any point in the comic. Also he is shown in his stereotypical deerstalker hat, which he never wears in the story at any point.
With the Swamp Thing ongoing series beginning in 2011, the first four covers depict the titular Swamp Thing. The only problem is that, for the first several issues of that run, Alec Holland wasn't even the Swamp Thing. It's only later that he actually changes into the Swamp Thing. The covers depict events that, while vaguely related to the contents of the issue, are horribly inaccurate.
Most modern comic books have different artists for the cover and for the comic book itself. The cover may not lie about the content, but about the style. You may buy a comic book with a magnificent cover and find that the interior art is drawn by a different artist, with a completely different style.
Spider-Man 694 features the end of a story arc involving 'Alpha' a teenager imbued with potentially the strongest powers in the Marvel Universe thanks to an experiment by Peter gone awry. As well as these powers, he's also become a selfish jackass, causing Peter to try and remove his powers before something bad happens. The cover of course features Spidey and Alpha high in the air, ready to beat the other into a pulp, with the words 'Battle Of The Half Century' hovering over them. The actual book? Well, they and the Avengers fight Terminus, but not a single punch is thrown between Alpha and Spidey; there isn't even a shouting match for them to exaggerate.
One of the Spider-Man graphic novels, the one collecting the Ends of the Earth storyline, does this in a relatively minor way. It should be obvious that Ock isn't actually going to fight Spidey in open space above the Earth and that that's just a cool cover, but Spidey is seen on the cover in his classic garb, when he spends 90% of the book in his new Spidey-armor, and only wears his classic outfit in the first book in the collection (and it's not used to fight Ock).
Shortly after the Batmobile was introduced in the comics (Detective #362) following the Adam West movie and TV series, (the first of which looked nothing like the Lincoln Futura Batmobile), it slowly started to resemble◊ the Futura more and more (Detective #371 and #375, though later issues change it to look like a Jaguar E-Type), the cover of Detective #375 has Robin drving the Batmobile and Batman waving to a crowd. The Batmobile does not appear in that issue.
In Death of the Family, one cover shows Harley Quinn and Joker going back to their abusive relationship. However, it turns out that there is nothing romantic between them, and Joker tries to kill her off as well as revealing that she's just part of a long chain of Harley Quinns that he has killed off at one or another. She escapes him and lets herself be put into prison.
An interesting subversion occurs on the cover of Love and Capes: What to Expect #5. In the story the Crusader (Mark Spencer) and his pregnant wife Abby switch bodies, but on the cover they don't switch bodies but just the suits (and now Mark has the "baby-belly") in order to convey what happens without words.
On the cover for Marvel Comics's Our Love Story #24 depicting the story "Joe Howard's Chick", protagonist Connie Smith doesn't appear to notice the boy approaching her and being stopped by another boy. Her noticing this is the turning point of the story. Compare the cover◊ to the actual scene◊.
If you've never read Garth Ennis' Preacher, the cover of the first issue can easily fool you into thinking that the hero, Reverend Jesse Custer, is the primary antagonist of the series (or at least a Villain Protagonist) even though he's one of the most sympathetic protagonists that you're likely to find in a Vertigo Comics book. How misleading is it? See for yourself: it's currently the page image for Sinister Minister, a trope that Jesse is emphatically not an example of.
The cover of the BIONICLE comic To Trap a Tahnok shows a Tahnok stealing Tahu's Golden Mask and another placing a mind-controlling Krana on his face. No event like this ever happens in the comics or books. One panel does show a random Lehvak Va carrying Tahu's mask, but when Tahu himself shows up in later, he has his mask on as if nothing had happened. The writer later explained that his losing and regaining his mask happened between scenes.
The 19th issue of Batman spinoff Batwing features the titular hero crawling on the ground, badly wounded and desperately trying to get away from a sinister looking Batman. The cover headline even read "A HERO FALLS..." This seemed like a big deal, since DC had already announced that David Zavimbe would be replaced in that issue by a new hero who would inherit the name of Batwing. The implication on the cover was that David would die, and that Batman was somehow responsible. In the issue itself, David simply decides to retire, and Batman is nothing but supportive.
Most of the revealed covers for My Little Pony: Friendship Is Magic (IDW) are sort of just generic "ponies being cute/cool" and very few so far even hint at the return of changelings. Not that we don't expect ponies being cute/cool or anything, but Rainbow Dash doesn't go snowboarding or dressing up as a superhero in Issue #1.
By far the worst offender is Friends Forever Issue #14, where the cover depicts an epic battle between Princess Luna and a pair of fierce-looking adult dragons. The actual comic had little to no Luna at all, the only dragons to appear matched the teenagers from Dragon Quest, and rather than fighting the story was a dialogue-heavy and veryAnvilicious allegory about racism. Fans were not pleased with thisnote Though the cover was only one of many reasons, and one fan actually slapped a disclaimer on the cover◊ to mock the blatant Wolverine Publicity.
Covers for The Frankenstein Monster would often depict women in peril, when none in the story is not in peril at all. However, the most misleading cover goes to issue 15, which depicts several Night/Clone-Creatures surrounding the Monster, while the one and only is featured in the story.
One issue of Joss Whedon's run on Runaways had a variant cover featuring zombified versions of Gert Yorkes and Alex Wilder. Only Gert appears at any point in the arc, and only as a hologram.
The cover of Avengers Academy #31 (published during the "A vs. X" event) featured several of the younger X-Men, like Dust and Surge, being delivered handcuffed and collared into an area surrounded by a chain-link fence topped with barbed wire. In the issue itself, they're dropped off at Avengers Academy by Wolverine, who's seeking to keep them safe from the fight between the X-Men and the Avengers. None of the kids are particularly happy about it, but they're never put in restraints.
Quasar #29. The cover depicted Quasar as pregnant, parodying the famous Demi Moore Vanity Fair cover. In the comic, while the character named Her does begin the process that will eventually make Quasar (and several other male superheroes as well) incubate a child, Quaze is able to talk her into cancelling it before any reproduction even occurs, much less the full-term that the cover showed.
Earth 2 #7 is titled "Flight to the Death!", showing Green Lantern and Hawkgirl fighting hand-to-hand on the cover. In the story, all they have is an argument over Alan not joining the team.
One cover for The Return of Bruce Wayne shows Batman in pirate garb over his costume with a massive beard and on a ship. In the actual issue, Bruce Wayne without his costume is sent to a beach in the 1700's, where he gets accosted by pirates. After they force him to lead them through a booby-trapped cave in search of treasure, he turns the tables and defeats them, then is sent forward through time. Not once does he set foot on a ship, and the experience only lasts a few hours, not long enough for Bruce to grow facial hair.
The Incredible Hulk#442 - about the only thing they got right is that She-Hulk is starring in the issue (Hulk being MIA). There are no 40 foot monsters anywhere nears this story.
The cover shows Victor Stone with most of his body converted to metal, making him resemble his mainstream counterpart. His condition never gets that far along in the book.
Starfire, as always, is depicted with the usual red-hair in the book, but is shown bald on the cover. She also never wears the purple shawl that is on the cover.
Ms. Marvel #15 depicts Kamala "Ms. Marvel" Khan and her crush Kamran chatting in high school halls while Kamala's brother Aamir looks on disapprovingly and Kamala tries to hide her Ms. Marvel domino mask in her pocket... but she was found out by Kamran two issues ago, one issue ago instead of taking her to school he outright kidnaps her, and #15 consists of Kamala's escape from captivity while Kamran goes full supervillain lackey, all with Aamir nowhere in sight all issue.
The Chick Tract "Home Alone?" features on the cover a small boy barely more than a toddler shivering in a corner while clutching his teddy bear. The sexual abuse victim introduced in the story is actually a 9th grader who still needs a baby sitter because reasons.
Halo: Uprising's covers show Master Chief doing things he doesn't do in the comic, like piloting a Brute Chopper or wielding a beam rifle on some alien world. It also doesn't show the actual protagonists of the comic, civilians Ruwan and Myras.
Superman #299 features Superman surrounded by various members of his Rogues Gallery while being completely invisible except for his super suit, as the text asks, "Which of his 9 deadliest foes did this to Superman?" This issue is the conclusion of a story arc where Superman discovers that he mysteriously loses his powers as Clark Kent and experiments with living as one of those identities full time, with the transformation as depicted in the cover being completely incidental (and, for the record, Mr. Mxyzptlk is responsible).
From the Old Man Logan tie-in for Secret Wars (2015), there's issue 2. The cover depicts Old Man Logan in a fight with a version of the mainstream Wolverine. Not only is the fight not in the issue, but said mainstream Wolverine himself isn't in the issue, he's merely mentioned in passing.
The first issue of the Thors tie-in for Secret Wars (2015) depicts Lady Thor on the cover, in the center of the group. Not only is she not in the issue, but the actual plot of the series involves investigating the murder of the Jane Fosters of Battleworld. In fact, every version of Thor depicted on the cover appears, except for Lady Thor.
The "classic" Sentry comics in The Age of the Sentry carefully recreate this particular disease of the Silver Age. "Oh no, not NOW, when the Sentry has been turned into a child!" says a lady on the title page; no infantilization actually occurs in the story. "Sorry to interrupt your super-wedding, Sentry..." gloats the villain on a later title page... Nope, ain't no weddin' to be found within.
One that generated a significant amount of attention was the cover to All-New X-Men #20, which features X-23 leaping into the arms of the time-displaced teenaged Cyclops and giving him a passionate kiss. Scogan shippers had a field day with it, many others were no less amused by the troll of Wolverine's Opposite-Sex Clone hooking up with Cyclops's younger self, while even more were infuriated. Of course, nothing even close happens in the book itself. The most that happens is Scott gives Laura an awkward, though kind of sweet, comforting hug when she's on the verge of breaking down over Murderworld.
Tales of Suspense #67 has Iron Man fight against a group of recreated supervillains, which according to the cover include the Colossus, who had been an opponent of Ant-Man and The Wasp in Tales to Astonish. The actual story instead features a different giant villain, Gargantus, an actual former foe of Iron Man.
Early 60's covers for Harvey's Richie Rich averted this, as the TOC page was a version of the cover. Later reprints kept the cover, but omitted the TOC page.
The cover to Titans Hunt #1 shows the Justice League and the modern Teen Titans standing solemnly at the grave of the "Forgotten Titan" ( who is revealed to be the original Dove in the final issue). The scene on the cover never occurs, and neither of those teams appear in the series at all.
On the cover of Batgirl #12, Batgirl is shown locked in a fight with Batwoman and seems to have the advantage, choking her with one hand and getting ready to sock her in the face with the other. In the actual issue, the "fight" between the two is a mix of Let's You and Him Fight and Working the Same Case, and Batwoman curbstomps Babs in just a few panels, without taking a single hit.
Some of the covers and promotional material for Ultimate Comics: X-Men showed Jimmy Hudson wearing a classic-style yellow Wolverine costume, complete with the iconic mask. He never once wears this suit at any point during the series, and while he did gain the costume in his solo mini-series, he still never actually put it on.
Spider-Man Vol.2 #9 (the Miles Morales volume) has a pretty egregious one. As seen on this page, a cover may show a hero fighting a villain, only for the issue to only show the villain preparing to fight the hero and setting things up for a future issue, or for the issue to end right as they meet. As such, fans often expect this sort of thing, so if an actual fight doesn't occur in the issue between the hero and villain, they at least suspected it and aren't too disappointed. The cover to this issue? Miles desperately fighting Venom. Not only does Venom not appear in the issue at all (no fight, no setup for a future appearance, not even a single mention of him in the issue), but Spider-Man himself barely appears. It's an issue that focuses mostly on his supporting cast worrying about where he could be.
The cover of The Unworthy Thor #5 shows Thor holding Ultimate Mjolnir while Thanos tries to wrestle it away from him. In the actual issue, Thor never lifts Mjolnir and Thanos never confronts him, since he's on the other side of the universe while this is all happening (instead, it's his enforcers who fight Thor).
The solicited cover for The Mighty Thor #20 shows the new Ultimate Thor with a gray beard, even though it isn't actually that color in the story or on the finalized cover. This was to hide the twist that the new Ultimate Thor was Volstagg.
Speaking of Thanos, the "Rebirth of Thanos" arc from Silver Surfer (the prelude to The Infinity Gauntlet) had several examples. The cover to Silver Surfer #36 promised "special appearances" by Adam Warlock and Captain Marvel, even though in the actual story, they only appear in Flashbacks or archival footage. In fact, at the time, Mar-Vell and Warlock had already been dead for a few years. The cover for issue #38 then showed the Surfer facing down Thanos, with the cover promising that only one of them would survive their final battle. Neither one dies in the actual issue, and the only real death is that of a disposable Mook who had been surgically altered to look like Thanos.
Some of the covers for the Madballs comic book published by defunct Marvel Comics subsidiary Star Comics depicted inconsistencies regarding what happened in the stories and what Madballs were present in the story.
The cover of the seventh issue, which served as a tie-in for the Madballs Head-Popping Action Figures, depicted Horn Head even though he was absent from the story and the only Madballs that were shown getting bodies were Skull Face, Dust Brain, Slobulus, Snake Bait, Lock Lips, and Wolf Breath.
The eighth issue's cover showed Dr. Frankenbeans' assistant Snivelitch turning into a baby alongside the Madballs Wolf Breath, Touchdown Terror, and Horn Head, when only the Madballs became babies in the actual story and the ending had Frankenbeans and Snivelitch turned into children rather than infants.
Slobulus appears on the cover of the tenth and final issue refusing to enter Dr. Frankenbeans until he's rinsed. In the actual story, Touchdown Terror, Fist Face, and Bash Brain were the only Madballs present.
Covers for IDW's More Than Meets the Eye tend to be of Mundane Made Awesome - which may or may not actually happen at all in the issue. One of them featured Swerve cleaning glasses in his bar. The Revolution One-Shot Crossover showed Misfire and Spinister eating at a fast-food resturaunt with humans when the story was actually about Crankcase meeting somebody over the Internet.