According to some accounts, Elongated Man was created because there were doubts as to whether DC Comics owned Plastic Man, despite ostensibly acquiring all of Quality Comics' (Plastic Man's original publisher) assets. Quality Comics characters' legal status was murky, however. Ironically, Plastic Man turned out to be one of the few Quality characters DC Comics actually owned outright. Artist and co-creator Carmine Infantino plausibly contradicts the above theory, however. He started as a one-off rival to The Flash, one who wasn't expected to be an important ongoing character. Infantino also says he wasn't consciously thinking of Plastic Man at the time, though "It must have been in the back of my mind. I loved Jack Cole's work, so it had to be in my mind, maybe instinctively."note Carmine Infantino: Penciler, Publisher, Provocateur (2010 book)
Justice League Unlimitedlampshades this when Elongated Man points out he's basically what Plastic Man would be if he was a detective. In one episode, he's relegated to crowd control, as Plastic Man is already fighting the monster off-screen, and, as Green Lantern tells him, "We don't need two stretchy guys."
Parodied further on Batman: The Brave and the Bold, in which the two of them are incredibly competitive with each other, to the point that an argument over who Batman prefers as a partner causes the criminal they're chasing to almost get away. After cleaning up their mess, Bats settles the matter by saying "Actually,I prefer to work alone."
The difference does get pointed out by Ralph that Plas is the jokester ex-con. Elongated Man is the ex-police detective. Also, one's powers are inherent, while Ralph has to drink a special formula to gain his powers.
The alleged influence Plas had on Ralph's creation is lampshaded, with Plas calling Elongated Man a "D-list doppleganger".
When Elongated Man first joined the Justice League, he wore a red costume with a black V-neck and yellow belt, rather than the more familiar purple outfit Infantino had given him.
In The Dark Knight Strikes Again, the two are shown to have something of a rivalry. However, there are clearer distinctions. This issue makes it clear that Plastic Man is the stronger of the two (being able to morph his body into anything while also stretching), but Elongated Man has the advantage of still being sane, unlike Plastic Man, who was stuck in the shape of a silly putty container for years until Batman literally punched sense into him.
Heck, this issue showed that Batman was wary of Plastic Man, even indicating that Plas could've killed them all if he wanted.
Zauriel was created by Grant Morrison and Mark Millar as a stand-in for Hawkman, who had been retconned so badly that he was unusable. Morrison made it a point to lampshade this so readers would get the point, too. The first time he sees Zauriel, Aquaman momentarily mistakes him for Hawkmannote "Katar?". Later on, Superman invites him to join, saying, "there's always room in the Justice League for, well...a big guy with wings like you." At one point, he and the then-new Hawkgirl Kendra Saunders bumped into each other when they flew.
In Morrison's X-Men run, he introduces a character named Fantomex who is based on the classic pulp characters Fantômas and Diabolik.
For the Watchmen project Alan Moore was initially commissioned to incorporate the classic Charlton Comics characters (which DC had just purchased) into the DC Universe. However, DC did not want to have several of the characters they had just bought killed off and/or rendered unusable, therefore, by mutual decision of the author and publisher, Captain Ersatzes replaced the original characters. Before being changed to Charlton, the plan was to use the MLJ/Archie heroes that DC had rights to at the time. Thus, many superheroes in Watchmen are Captain Ersatzes of Charlton heroes, or MLJ/Archie for the earlier generation:
Dollar Bill -> The Comet (one of the first superheroes to die)
Silk Spectre I -> Fly Girl
Nite Owl I -> Blue Beetle I (Dan Garrett), and/or The Black Hood (similar costumes)
The Comedian -> The Web (similar costumes, and The Web's domineering wife is reversed as an attempted rape)
Moore loves this trope and reuses it in Providence, his Lovecraft meta-origin story. Most Lovecraft characters, as well as locations such as Arkham, are renamed. The exceptions so far are Robert Suydam and Thomas Malone from The Horror at Red Hook. Moore is not dealing with copyright issues, as Lovecraft has lapsed into public domain (as shown by Cthulhu commonly appearing in horror work). Instead it appears that Moore is suggesting that in-universe Lovecraft took the characters and locations depicted and wrote about them in his stories, merely changing their names. However Moore could not do this with Suydam and Malone as they were already named in "Neonomicon", so he used their original Lovecraftian names.
Doctor Muñoz from Cool Air is Dr. Alvarez, Obed Marsh from Innsmouth is Jack Boggs and the Marsh Refinery is likewise renamed as the Boggs Refinery. The Whatelys from "The Dunwich Horror" are now the Wheatleys. Dr. Herbert West becomes Dr. Hector North, Asenath and Ephraim Waite become Elspeth and Edgar Wade, Keziah Mason becomes Hezekiah Massey, Richard Upton Pickman is Ronald Underwood Pitman and Randolph Carter is now Randall Carver. The Church of Starry Wisdom becomes the Order of Stella Sapiente.
In the case of locations, Moore simply transplants the fictional locations used in Lovecraft's prose to the real-life equivalents cited by Lovecraft himself as his inspiration for the renamed landscapes in his works (with letters citing the inspiration printed on the back cover of each issue). Innsmouth is Salem, Arkham is Manchester, Dunwich is Athol. Miskatonic University is now the real-life Saint Anselm's College whose exterior facade is accurately reproduced in the book.
Marvel Comics' Deadpool (a.k.a. Wade Wilson) was originally a Captain Ersatz of DC Comics' Deathstroke the Terminator (a.k.a. Slade Wilson); co-creator Rob Liefeld had previously worked with the original Deathstroke character during his term on the Teen Titans series. Deadpool quickly became a distinct character under the handling of various Marvel writers, to the point that all they really have in common now is being masked mercenary/assassins.
Later, at DC, long time Deadpool writer Joe Kelly paid tribute to this origin in Superman/Batman Annual #1, where the Earth-3 counterpart of Deathstroke appeared as a thinly-disguised version of Deadpool, who was always interrupted before he could finish telling people his name. The comic was also drawn by Ed McGuiness, who worked on Deadpool's solo series for a very long time, beginning with the very first issue.
Years after that, former Deadpool writer Jimmy Palmiotti created a similar character named Red Tool in Harley Quinn. The character was seemingly created in response to the popularity of Deadpool and Harley as a Crack Pairing.
When Liefeld was dismissed from the Heroes RebornCaptain America series, he decided to re-use the unpublished art as a reprise of Joe Simon's character Fighting American, but licensing delays led to the interim creation of Agent America. He had some legal trouble from Marvel for his Fighting American series; namely FA was way, way too much like Cap, even having a round shield that he would throw. Liefeld had to be content with a Fighting American who did not throw his shield.
Mark Millar's Wanted. Originally it was a Legion of Doom Reboot and got shut down. So Mark Miller made it Darker and Edgier and changed the names. It's really obvious who most of the characters are supposed to be.
British Comics Example: Thirteen-year old nerdy orphan who lives with an aunt and uncle, Billy Farmer gets scratched by a radioactive leopard. He begins to gain powers like those of a big cat, speed, strength, agility, night vision and a 'Leopard Sense' that tingles in the presence of danger. He takes to wearing a leotard in leopard spots and crime fighting as Leopard Boy/Leopard Man/The Leopard from Lime Street (series title). Actually a very good Spider-Man rip-off with a British setting and nicely altered characters and powers.
Another British comics example: In the 50s, when British publisher L. Miller ran out of Captain Marvel stories to reprint, he commissioned Mick Anglo to create a similar superhero, Marvelman (known in America as Miracleman). Due to the exceptional quality of these stories (particularly Alan Moore's 1980s revival), Marvelman/Miracleman became a beloved character in his own right.
Still another British comics example: In Zenith: Phase III, Grant Morrison used thinly veiled versions of characters owned by 2000 AD's rival comic publishers. Those he could actually get the rights to just appeared as themselves.
The original Doctor Who comic strips didn't have the rights to the Daleks at first, so they used similar enemies called Trods. Eventually the company did get the rights to use the Daleks, so they took advantage of it by creating a storyline in which the Daleks EX-TER-MIN-ATE the Trods!
The original comics also didn't have the rights to use the real companions, only the character of the Doctor. Thus, John and Gillian were introduced, a pair of Ridiculously Generic Grandchildren, both of whom were modeled slightly after the Doctor's canon grandchild Susan but both of whom were also younger and Lighter and Softer (and significantly duller as a result).
The Trod situation and the companion situation were parodied in an Eighth Doctor strip pastiching these original comic strips, in which the Eighth Doctor and his grandchildren John and Gillian battle ridiculous, vaguely Dalek-shaped monsters◊ called Wargonns. Deconstructed when we realise the adventure is All Just a Dream in which the Doctor is fantasising about a happy life.
The TV Comics Magazine strips had rights to use likenesses of the companions, but would occasionally find themselves contending with companions leaving while the strips were being drawn (or when rerunning a Second or Third Doctor strip with the Doctor retouched to resemble the current imcumbent to save money). Examples include Sarah Jane and Brigadier Lethbridge-Stewart being converted into the identical "Joan Brown" and "Colonel Maxwell-Lennon" for one story, and "Miss Young", a miniskirt-wearing companion who has Leela's overly-formal speech patterns and attempts to kill people with knives.
Marvel Comics also created eccentric time-traveler Professor Gamble and his enemies, the marauding robot army of Incinerators, Ersatzes (Ersatzii?) of Doctor Who's Doctor and the Daleks respectively, with Shout Outs galore. Rather odd, since Marvel UK published Doctor Who comics at the time, and the Doctor had already interacted with mainstream Marvel Universe characters.
Nearly all the (non-series-star) characters in Planetary were created as Captains Ersatz of some existing character or trope, simply so the Planetary team could interact with visitors from many continuities.
Superman has Captain Marvel (now an inhabitant of the same comics universe), Hyperion (Marvel), Mister Majestic (who has actually met Superman and briefly replaced him), and Supreme. In the MMORPG City of Heroes, Statesman occupies this role. Tabletop RPG versions include The Sentinel (Silver Age Sentinels), Protonik (Mutants & Masterminds, 1e), Axiom (Villains & Vigilantes), and the Centurion (M&M 2e).
There are several Ersatz in Irredeemable, much like with Watchmen. More notable ones include the Hornet (Batman), Gilgamos (Hawkman), Orian (Mxyztplk), Modeus (Brainiac), and Alana Patel (Lois Lane).
There is also Alpha One from The Mighty who has all of Superman's powers. He even has a secret headquarters.
Milestone Comics' Icon is also something of a What If? Superman ("What if Superman's rocket crashed in the Deep South circa 1840... and he was black?")
Blue Marvel is another What If? Superman ("What if Superman were a black man in the 1960s?"), complete with his own Fortress of Solitude-like Home Base.
An unofficial action figure example is Captain Ray, AKA: El Capitan Rayo, which was basically a series of Superman action figures from the DC Superheroes Collection, repainted to be a new character when imported to Brazil (the red boots and trunks were repainted to be yellow and the famous S-insignia was replaced with a Flash Gordon style lightning bolt insignia).
The Anchor of Justice in The Shadow Hero is a Superman Ersatz who acts as the hero's inspiration, right down to secretly being an alien, although a less humanoid one than Kal-El.
Superman: "I nominate Icon for League membership."
Green Arrow: "Why? Because you think he might be Kryptonian, like you did with Captain Marvel?"
Iron Munro is basically the Golden Age Superman (though he's supposedly a descendent of Hugo Danner in a Development Gag) with Doc Savage's design, as he was explicitly created to fill the gap in the team when Superman became unusable.
Along with Mister Majestic above, WildStorm also boasts The High (Superman if he got burnt out on superheroing and decided to take more drastic measures to change the world) and Apollo (same powerset and power source, same role in the team, and he's close to a Batman expy... namely, his his husband). Ironically, it's considered a Crapsack World.
Mr. US is unique among Big Bang characters for a) being based on a Marvel character, Captain America, and b) being used to satirize comics rather than celebrate them.
In the last issue of the Image Comics run, Big Bang's Round Table of America faced off against 1963's Tomorrow Syndicate — essentially Ersatz DC vs Ersatz Marvel.
Hack/Slash has sometimes included flashback panels of old enemies who haven't appeared in the actual comic yet, many of whom are veryrecognisable. The slasher "X-O", who makes a more substantial appearance, is very clearly a hybrid of Pinhead and Mr. Zsasz. Also, the "Wunderkind" superhero comic that exists within the story is clearly a stand-in for Captain Marvel, probably fictionalised because of the unflattering depiction of its fans.
In Astro City, virtually all of the characters — hero, villain, or otherwise — are directly based on more established comic book characters. Of particular note are the Samaritan (Superman), Winged Victory (Wonder Woman), and the First Family (the Fantastic Four). Batman has analogues in the Confessor (brooding night vigilante with a young sidekick) and Leopardman (animal theme, and mentioned as having been suspected to be Anders Van Rupert, a millionaire with a butler). The Lamplighter is probably meant to be reminiscent of Green Lantern, but he's only really been referred to and never actually seen.
Harry Dresden also uses many tropes identical to John Constantine (see Trench Coat Brigade), and was created 15 years after John's first appearance by a fan of 80s and 90s comics.
The Marvel Retcon series Marvel: the Lost Generation includes an ersatz Batman called Black Fox (millionaire playboy Dr. Robert Paine) with an Elaborate Underground Base called the "Fox Hole", a plane called the Flying Fox, a former Kid Sidekick, etc. His sidekick grew up and teamed up with the empathic healer Nightingale, a Captain Ersatz of Teen Titans' Raven.
Jack Kirby created The Eternals as deliberate Captains Ersatz of the Gods of Greek Mythology and several other pantheons, with the idea that their adventures had "inspired the myths". For example, Makkari inspired Mercury, Ikaris inspired Icarus, Phastos inspired Hephestus...
Which became interesting when the Eternals, who originally did not interact with other Marvel heroes, became part of Marvel canon, which includes the Greek gods and Hercules...
Which is the reason for the eventual retcon that they were confused with the gods they resemble; Gilgamesh the Forgotten One even accidentally performed one of Hercules' Twelve Labors for him (the Aegian Stables, fyi)
The Shi'ar Imperial Guard, introduced in X-Men vol. 1 #107, began as an ersatz Legion of Super-Heroes. Electron is Cosmic Boy, Hobgoblin is Chameleon, Smasher is Ultra Boy, etc. Not surprising that writer Chris Claremont and artist Dave Cockrum would do this, since Cockrum had become famous drawing the Legion for DC before he co-created the All-New, All-Different X-Men (he had in fact offered Nightcrawler as a potential Legionnaire before, only to have him rejected as too weird-looking). In particular there is a strong resemblance between Superman (or the pre-Crisis Superboy) and his expy Gladiator, which was lampshaded by naming him after the novel that is generally believed to have inspired the creation of Superman, and who eventually got the real name "Kallark" (sounds like "Clark" and Kal-El, doesn't it?). The Gladiator also has a similar chest insignia and costume, but his powers are psycho-active (he can only do something if he believes he can) and he has purple skin and a huge mohawk.
In later stories, the Imperial Guard was expanded with members who do not have an equivalent in the Legion, e.g. Hussar and Cerise.
Interestingly, the postboot Legion featured Gates, who may be an ersatz of an Imperial Guardsman who didn't have a clear Legion parallel previously.
Proceeding from the fact that the Imperial Guard were originally enemies of the X-Men, some fans like to think that they arguably work as a deconstruction of the Superman mythos. They show what it might have been like if, instead of landing on Earth, Kal-El had wound up in some autocratic, politically unstable Alien empire where he was made to serve whatever ruler sat on the throne. Without Superman's moral center, Gladiator's just a blindly obedient thug. Or big on Honor Before Reason, depending on the writer (obeying his oath to the Shi'ar throne even when he knows the current emperor is insane and wants to do something about it). Although since the Imperial Guard appeared for ages without origins etc., that may be going a bit far.
While we're at it we should talk about Mighty Man; he was created by Erik Larsen as an ersatz "Shazam!" Captain Marvel. Besides being a supporting character in The Savage Dragon, he appeared as the Captain Marvel equivalent in both Supreme and Big Bang Comics — despite Big Bang having already established Thunder Girl as a less-direct analogue for CM. Big Bang also used him as an ersatz Captain Mar-Vell in one issue, interestingly enough.
This connection gets a gigantic Lampshade Hanging in JLA/Avengers, where after spending a few minutes going "Who do these guys remind me of?", Hawkeye finally declares the JLA to be Squadron Supreme wannabes.
Avengers: No Surrender adds Victory to the original Squadron Sinister lineup, who not only shares Triumph's costume and powers, and has a synonymous name, but even shares his "founding member of the team wiped from history" backstory.
Buck Wild from Milestone'sIcon is a Captain Ersatz of several different characters. His original costume and powers are clearly based on Luke Cage, he later wore a suit to fly and teamed up with a patriotic hero like The Falcon, got a special belt that gave him the power to shoot electricity like Black Lightning, and then finally became a grim soul avenger like Spawn.
Pretty much every villain faced by DC's Inferior Five is a Captain Ersatz of a character from a rival publisher. The evil agents of H.U.R.R.I.C.A.N.E. are based on the T.H.U.N.D.E.R. Agents, the Kooky Quartet on the Fantastic Four (with the nickname given to the Avengers after their first big roster shakeup), etc. Their version of Thor even mentions a comic book deal with a guy named Stanley, though he has to shave his beard off and bleach his hair blond first… Not to mention the Freedom Brigade, the parents of the Five themselves: Merryman (son of The Patriot and Lady Liberty), Awkwardman (son of Mr. Might and The Mermaid), Dumb Bunny (daughter of Power Princess), The Blimp (son of Captain Swift) and White Feather (son of The Bowman).
Black Cat is often thought to be a knock-off of Catwoman due to their extremely similar costumes and motifs, as well as their forbidden romances with superheroes. However, this there is a good deal of contestation. Black Cat was conceived as a foe for Spider-Woman, and Catwoman did not start wearing her iconic black leather outfit in the comics themselves until the 80's, long after Black Cat debuted. Though it must be noted however that Catwoman actually did wear such an outfit in the popular television show from the 1960's starring Adam West as seen played by Julie Newmar and Eartha Kitt. Whatever the case however, the Black Cat as conceived for Spider-Woman had little in common with the one that saw light in Amazing Spider-Man - she was supposed to be an outright heroine dressed in a 1930s style costume and a hat. When Felicia Hardy - a cat-burglar infatuated with Spider-Man - appeared, it seemed everybody except her creator Marv Wolfman saw the strong resemblance to Catwoman.
The Ultramarine Corps in JLA Classified were light Ersatzes of The Avengers and other miscellaneous Marvel heroes. The Olympian had power from the gods but was a little nutty (Thor), Goraiko is a giant atomic monster (Hulk), Warmaker-One is an uber-patriot who only exists inside a high tech exoskeleton (Captain America/Iron Man), the Glob is a Boisterous Bruiser who calls himself "ever-lovin'" (The Thing), etc.
Loose Cannon, one of the heroes introduced in DC's much maligned Bloodlines event (although he was actually one of the better ones), is a strong Ersatz for the Hulk, in that his power is connected directly to his anger, he's incredibly bulky and brawny, and lacks a certain intelligence. Loose Cannon's only original hook is that he has different stages of power, and his skin color changes as he climbs his little rage ladder.
The Flashback Universe is all about this for classic Marvel. Saturn Knight is Nova, Wildcard is Spider-Man, Fantom Force is the Fantastic Four, Lady Nemo is Dr. Doom, Terrorsaur Rex is the Hulk, Prometheus is Thor, Paladin is Captain America, the Legion of Monsters are the X-Men, the Vanguard are the Avengers, the Sub-Terrainer is the Submariner...
Jeph Loeb had a thinly veiled Avengers team show up in Superman/Batman, called the Maximums (complete with a battle cry of "MAXIMUMS, MARCH!"). The name seems to specifically recall the Ultimates, whose comic, ironically enough, Loeb would go on to write.
Soldier — Patriotic hero, counterpart of Captain America
Viking — Nordic God, counterpart of Thor
Hornet — Half-human half-insect flying heroine, counterpart of Wasp
Skycraper — Giant man in love with Hornet, counterpart of Giant-Man
Robot — Conscious robot in a bulky iron-suit, counterpart of Iron Man
Bowman — Archer, counterpart of Hawkeye
Wolfen — Bestial wolfman with tiger stripes, counterpart of Wolverine
Bug — Blue and red four-armed man, counterpart of Spider-Man
Monster — Big creature with super-strength and ripped pants whose alter ego is weaker, counterpart of Hulk.
Nightveil/The Blue Bulleteer from AC Comics' Femforce was originally the Phantom Lady from Fox and Atlas Comics (the character was originally created for Quality, who did not contest the use by Fox, long story), but when DC claimed ownership they hastily changed tiny minuscule details like the name and the color of her costume. Yep, she is totally not Phantom Lady. To be fair, she eventually got magic powers and a new costume and became a totally distinct character.
In a Blue Bulleteer one-shot, the Blue Bulleteer runs into another hero using the same name as her - this one an ersatz version of Fawcett Comics' Bulletman. It even featured a backup story starring the other BB, which was really just a slightly edited Golden Age Bulletman story.
DC's Boss Bosozoku and his successor Boss Bishounen are both motorcyclists with heads on fire. Ghost Rider, right?
Possibly not, or at least not entirely; all the Big Science Action team appear to be based on Japanese tropes. On the other hand, his teammate Cosmo Racer is very blatantly the Silver Surfer (as well as being Astro Boy), so maybe.
The Final Crisis art book specifically mentions AKIRA as an influence on Boss Bosozoku.
And while he doesn't resemble him much as a character, Big Atomic Lantern Boy's design is plainly based on Hayashida from Cromartie High School.
In The Intimates, Mr. Hyde is a clear Superman parallel; Hyde is actually his real name and a joke about Superman's obvious dual identity, he wears glasses and teaches the Secret Identity class, he's squeamish around reporters (it's his ex...), and has all the powers you'd expect. Most of the other seminary teachers are also ersatzen; the Principal used to be Mr. Big, a Giant Man type hero, while the school counselor was once Dash Man, an ersatz Flash. Interestingly, none of the main characters are ersatzen.
Dr. Everything, one of the Redeemer's patients in The Sinister Spider-Man, is an obvious Dr. Manhattan parody. He's a statuesque naked physicist with incredible power and his body is entirely red, as opposed to Manhattan's blue.
Monster Plus features Supermane, who is basically Lion-Head Superman from that one Silver Age story involving red kryptonite.
One issue of X-Man features an Expy of The Authority called the Protectorate: Niccola Zeitgeist (Jenny Sparks); Thor (Apollo); Nightfighter (Midnghter); Citydweller (Jack Hawksmoor) Professor X (the Doctor); White Bird (Swift); and the Technocrat (the Engineer.) Interestingly enough, many members of the Authority are themselves based off existing superheroes (Midnighter is Batman and Apollo is Superman), making this team Ersatzes of Ersatzes.
Top 10 featured the Seven Sentinels, a clear takeoff on the Justice League with members like the Black Boomerang (Green Arrow), the Hound and Kingfisher (both Batman), Atoman (Superman), and Davy Jones (Aquaman).
And many other more minor ones, like Trent "Dr. Incredible" Teller (Mr. Fantastic) and his wife Beach Ball (Invisible Woman), the Skysharks (Blackhawks), etc. The Blue Dart is another Green Arrow ersatz, as well. Interestingly, none of the principal characters are Ersatzen except for maybe Jetman, who is based on Airboy and Hop Harrigan. (Toybox is arguably inspired by The Beano's General Jumbo, but it'd be more accurate to call her father, Colonel Liliput, the Captain Ersatz.)
Mark Waid's Empire features a "Dr Doom esque" villain who conquers the world by defeating a Superman pastiche.
The characters of the Image miniseries Battlehymn form a clear and intentional parallel to the original Invaders. Quinn Rey is the Sub-Mariner (but also shares traits with Aquaman, the Fin, and the Golden Age Hydroman), the Proud American is Captain America, the Artificial Man is the Human Torch, the Defender of Liberty is also Captain America, but with a touch of the Patriot (Cap's counterpart on the homefront and replacement after he went missing), Johnny Zip is the Whizzer, and odd man out the Mid-Nite Hour is a combined Dr. Mid-Nite/Hourman/Batman, the only one to be based on DC characters.
Marvel's Ultimate Adventures centered around Batman pastiche Hawk-Owl and his sidekick Woody. Accompanying them was Hawk-Owl's butler Daniel (Alfred). He also had an Asian chauffeur based on The Green Hornet's Kato, and his Aunt Ruth is a combination of Aunt Harriet from the '60s Batman show and Spider-Man's Aunt May. And the Principal is a parody of the Joker and Two-Face.
Kill All Parents' heroes are all strongly based on famous Marvel and DC guys. The list is long, but to give an example you have the Locust and Larva Lad standing in for Batman and Robin.
Every alleged "hero" that Marshal Law finds himself up against is an Ersatz. The Public Spirit is Superman, the Private Eye is Batman, the Secret Tribunal blend elements of the X-Men and the Legion of Superheroes, the Jesus Society of America are the Justice Society of America (and include a Captain America-like Golden Age Public Spirit), the heroes holed up in a Manhattan asylum are all based on Marvel characters (and for the most part go unnamed). Pat Mills described Marshall himself as an unholy fusion of Captain America and Judge Dredd.
Hellboy's backstory features the Torch of Liberty, a thinly-disguised Captain America stand-in.
The Green Pedestrian Palm is blatantly Green Lantern; fittingly, a portrait of the real Green Lantern appears in the background of one panel. He's also heavily based on the Green Cross Man, a superhero created in The '70s to educate children how to safely cross the street.
The Authority faced off against Ersatzes of classic Marvel heroes in Mark Millar's inaugural arc. The Americans were obviously Avengers pastiches with named ones being the Commander (Captain America), Tank Man (Iron Man), Hornet (Wasp) and Titan (Giant Man) while the rest were clearly based on Thor, Hulk, Black Panther, Scarlet Witch, Hawkeye, and the Vision. Later, they took down unnamed Ersatz teams resembling the X-Men, The Inhumans, Fantastic Four (with additional Silver Surfer, Galactus, Watcher and H.E.R.B.I.E. knock-offs, all of which are most famously associated with the FF) and the Howling Commandos while other Wildstorm heroes fought Ersatzes of Spider-Man, The Punisher, Daredevil, Elektra, Doctor Strange, Namor and others. The story's Big Bad, Jacob Krigstein, was an evil ersatz Jack Kirby.
Stormwatch also featured The Changers, who were based on JSA members and other sources, including The High (Superman), Blind (a hybrid of Doctor Mid-Nite with Steve Ditko's later Objectivist heroes), The Doctor (Doctor Fate), The Eidolon (The Spectre and the Crow), The Engineer (Green Lantern), Rite (Wonder Woman), and Smoke (Sandman and the Shadow).
The Sons of Liberty, another group of Authority foes, are based on the Freedom Fighters: Paul Revere (Uncle Sam), Maiden America (Miss America), Dyno-Mite the Human Hand Grenade (Doll Man with elements of the Human Bomb), Johnny Rocketman (the Ray), and Fallout (the remaining elements of the Human Bomb).
Batman himself is a Captain Ersatz of Zorro: Rich playboys both missing mothers who decide to use their vast wealth to fight crime? Hell, Bob Kane himself admitted to it. There is in fact no attempt to hide this, as Batman watches a Zorro movie the night his parents die.
The original Guardians of the Globe in Invincible are clearly based on the original Justice League of America; the Red Rush is the Flash, War Woman is Wonder Woman, the Green Ghost is the Green Lantern, Martian Man is the Martian Manhunter, Darkwing is Batman, Aquarius is Aquaman, and the Immortal and Omniman are both Superman. They also had Black Samson, who seems to be based on Marvel's Doc Samson and Flash Gordon.
Damien Darkblood, Demon Detective, who is almost identical to Rorschach of Watchmen fame except slightly mellower.
And many of Invincible's minor enemies are based on Spider-Man foes. The Elephant is the Rhino, Doc Seismic is the Shocker, Kursk is Electro, etc.
And the Lizard League is a combination of G.I. Joe's Cobra and Marvel's Serpent Society. Komodo Dragon in particular is based on the latter's Puff Adder.
A case could be made that the new Guardians of the Globe are Captain Ersatz for the Avengers. Monster Girl for Hulk, armoured Black Samson and Robot for Iron Man, Shrinking Ray for the Wasp, and Immortal could take the role of Captain America due to his suspicious appearance.
In Rick Veitch's Brat Pack, Moon Maiden is an ersatz Wonder Woman, while the Mink and Judge Jury split among themselves the role of Batman (the Mink is a flamboyant millionaire whose superhero career is undermined by rumors of homosexuality, while Judge Jury is a brutal vigilante who gives no quarter to the criminal element), and King Rad is the Green Arrow. A pivotal part in each of their stories is the presence of an ersatz Superman who eventually abandoned the city.
Bob The Galactic Bum is an interesting example. During its original run, Lobo made an appearance as a supporting character. When it was reprinted in the Judge Dredd Megazine in the late noughties, they were unable to secure the rights to use Lobo. Thus, Lobo was replaced by a butch lesbian bounty hunter by the name of Asbo.
In a later issue of the Meg, Dredd went up against an amnesiac Canadian mutant codenamed Weasel, whose fingers have been replaced with 'unbreakium' claws. His skeleton has been swapped with solid Boing™, he had an incredibly powerful Healing Factor, and he tended to call people 'Bob'. As if he wasn't a blatant enough copy of X-Men'sWolverine, at the end of the story, he returns to his pseudo-family - this consists of a woman with a stormcloud perpetually over her head, a cyclops, a beastly chap, an angelic guy, and a big-headed bald man in a wheelchair.
Another Dredd storyline in 2000 AD had another mutant rights organisation organised by a bald professor, including An Ice Person, a redheaded telekinetic, a guy with wings and a bestial guy. The twist? They weren't really mutants at all.
And in another recent issue of the Meg Dredd took on a rogue PR judge and his team of "super-judges" called the Adjudicators. This issue also coincided with the UK release of The Avengers movie.
Bongo Comics' line of comics based on The Simpsons (and Futurama) features an occasional series of Radioactive Man comics (Bart's favorite superhero from the TV show) that pretends to be the "actual" comics from the Simpsons' universe, and parodies various superhero comic trends and styles from the 1950s through present (depending on the "year" the comic was "published"). In particular, Radioactive Man and his cohorts parody many comic elements:
Radioactive Man himself is Superman (Flying Brick powers, etc.), with elements of Batman (his alter ego as "Claude Kane, millionaire layabout", a teenage sidekick) thrown in. His origin story is basically the Incredible Hulk's.
Fallout Boy is Robin, with an origin story paralleling Spider-Man's.
Brave Heart/Purple Heart/Bleeding Heart/Heart of Darkness = Green Arrow (in background and liberal views); also has elements of Iron Man, in that he owns a weapons company and funds the Superior Squadron. Like Ant-Man, he constantly changes his superhero persona. Additionally, being the leader of the Superior Squadron, it's fitting that the overall shape of his costume resembles that of Captain America, and his heart themes parallel different eras for Cap.
RM's arch-nemesis Dr. Crab is basically Lex Luthor, with aspects of Dr. Sivana thrown in as well.
Similarly, in an early Simpsons Comics storyline where the citizens of Springfield (save Bart, though he later on does show up in his "Bartman" guise) accidentally gain superpowers, they wind up becoming Captain Ersatz versions of various superheroes:
Homer became the Inedible Bulk (including citing "the madder Bulk gets, the hungrier Bulk gets!" and "Bulk gnash!").
The Nigerian hero Powerman was intentionally created in order as a black version of Superman.
PS238 is made of this trope. Virtually every main character is a Captain Ersatz of some other company's characters.
Lampshaded and repeatedly played with in "Heal Thy Elf", an ElfQuest satire in that franchise's New Blood Special issue. At one point, the appearance of a thinly-veiled Charlie Brown Captain Ersatz is called out and derided ... by a thinly-veiled Captain Ersatz of the bugs from Pogo.
Justice League Europe once met a clan of Parisian Gargoyles named Behemoth, Seine, Angelique, Montparnasse, Montmartre, Champs-Elysse and Left Bank. Behemoth had an evil twin named Thomeheb and an ex-wife named Diabolique. The story was written by Greg Weisman.
The crime comic Kane has a hitman named Frankie who's basically Marv from Sin City, face bandages, interior monologue and all... until he speaks...
In Astérix and the Falling Sky (2005, original French title Le ciel lui tombe sur la tête) an alien leader named Toon is an obvious reference to Mickey Mouse (Uderzo, the comics creator, has said that this album was also a tribute to Walt Disney). The story also includes an army of Arnold Schwarzeneggers dressed like Superman, but with a star symbol in place of the "S".
Man-Thing had Wundarr, a version of Superman who is never rescued from his spacepod due to the paranoid temerity of a certain old couple. Instead, he grows up tutored by computers until accidentally released by the title character.
Alan Moore's Terra Obscura turned previously unrelated Public Domain Golden Age heroes the Black Terror and Tom Strange into ersatz versions of Batman and Superman. The other heroes were made to correspond very roughly to various other figures from the era, but none so much as those two.
Alan Moore also created the 1963 mini-series for Image, with each of the six issues being an homage to Marvel Comics of the 1960's: #1 Mystery Incorporated (Fantastic Four), #2 The Fury (Spider-Man and Daredevil), #3 Tales of the Uncanny (U.S.A and The Hypernaut = Captain America and Iron Man),#4 Tales From Beyond (Johnny Beyond and N-Man = Dr. Strange and the Hulk), #5 Horus (Thor), and #6 The Tomorrow Syndicate (The Avengers).
10th Muse supporting characters Venus/Mighty Maid and Wombat are, respectively, Supergirl and Batman (though both are female). Venus' introductory issue was an extended Shout-Out to the Supergirl mythos, as it were, and Wombat actually murders her own parents outside a movie theater because she thinks it will make her a better hero.
The Pro herself is a parody of Power Girl, sharing not only a prominent cleavage window and similar hairstyle (though much more disheveled). She also takes the Ms. Fanservice role quite a bit further by actually being a prostitute.
One of Marvel's earliest Golden Age heroes was the Angel, best described as "The Saint in a superhero context".
Marvel and DC have used this to foster a Fake Crossover on occasion. One month, Marvel's Invaders and DC's Freedom Fighters both faced off against a group known as the Crusaders. In both cases, the Crusaders were ersatz versions of the other company's team.
The Yellow Bastard is a horrific case in that Frank Miller has admitted that he was based off of a grown-up (and deranged) version of the Yellow Kid◊.
Holy Terror was originally meant to be a Batman story, as such some of its characters, despite Miller proclaiming it was no longer a Batman story, carry many superficial elements of Batman characters to the point that it may as well still be a Batman story. The Fixer is obviously Batman, Natalie Stack is Catwoman (to the point of cracking a "nine lives" joke) and Dan Donagel is Jim Gordon (the latter not even that different looking). Even Empire City itself shares much with Gotham, such as the Statue of Liberty-esque statue that some versions of Gotham have.
The mostly forgotten 1966 "Captain Marvel" from MF Enterprises had a rogues gallery composed almost entirely of Captain Ersatzes. Including guys called Plastic Man (later changed to Elastic Man), Dr. Fate, The Bat (Later changed to The Ray), Tinyman (Captain Ersatz of Dollman), and Atom Jaw (Captain Ersatz of Iron Jaw, arch-foe of the then-popular hero Crimebuster).
The Kindle-based comic book series Limekiller at Large features a number of these. The Blue Pangolin (The Ted Kord version of Blue Beetle), The Alloy Angel (Iron Man), Commander Dynamic (Superman), The Knoir Knight and Chickadee the Boy Diversion (Batman and Robin), Quantum Phyllis (Dr. Manhattan), and the American Ranger (a mash-up of Captain America and the Lone Ranger).
Much of the cast of Jack Staff is made up of Ersatz versions of either Marvel Comics heroes, or British pulp comic heroes. This is because the series was originally pitched as a Marvel series. Jack Staff himself is based on Captain Britain and Union Jack; Becky Burdock is partially based on Captain Britain's sister Betsy Braddock/Psylocke. The Hurricane is Captain Hurricane, Tom Tom the Robot Boy is Archie the Robot, and General Tubbs is General Jumbo.
During World War II, when Will Eisner was drafted and put his The Spirit series in near limbo, Quality Comics had commissioned Jack Cole to create a near copy, Midnight, who was visually almost exactly like The Spirit, but the stories were broader in comic scope. When the character had his own stories in the 1990s as a backup story to Ms. Tree at DC, he was changed to a darker tone and more enigmatic style to differentiate him from the still more famous Spirit.
Marvel's Dark Avengers, in a blatant attempt to cash in on the latest Dredd movie, featured the Dark Avengers travelling through time to Mondo-City 1, where a clone of Luke Cage's grandson dispenses justice as "Boss Cage" and shares many common traits with his inspiration (he never takes off his helmet, rides a souped-up bike with cannons mounted on the front, is unquestionably devoted to the law, has a gun coded to his DNA, and so on). Taking it further, the Outlands are the Cursed Earth, the blonde Boss Sanders is probably Judge Anderson, and a list of Boss Cage's former rogues includes "Boss Venom" (the Venom symbiote wearing a Boss helmet) clearly intended as a reference to the inhuman, pointy-toothed Judge Death.
Atomic Mouse vs Power Jack and the Lost Menagerie features the titular Funny AnimalAnimal Superhero meeting a dimensionally-lost superhero team led by a bunny rabbit in a yellow costume and red cowl, and including a metal pig, a magic cat etc.
In The DCU, the Scarlet Skier's skis allowed him to fly through space and act as the herald and cosmic locator for Mr. Nebula. They were clearly based on the Marvel Universe characters the Silver Surfer and Galactus, who had the same relationship.
During the "Dead End Kids" arc, the Runaways encountered a 1900s version of the Avengers, which included Difference Engine (Iron Man), Black Maria (Scarlet Witch), Nightstick (Captain America), and Daystick (Bucky). There was also a trigger-happy vigilante calling himself the Adjudicator, who was obviously a stand-in for the Punisher.
In the special anti-drug comics of Teen Titans in 1983, a licensing issue note Robin had been licensed by Nabisco for superhero themed cookies, while the comics were sponsored by Keebler led to the character of Robin having to quickly be redrawn as an auburn-haired, purple-clad character named "The Protector", who still acted as the leader of the Titans and did all the things that Robin normally would have. The Protector also appeared in an animated anti-drug ad by Hanna-Barbera, who was to also make a New Teen Titans animated series at the time (minus Protector and with Wonder Girl as the leader, though it never got off the ground). DC eventually tried to explain away the character's existence in the 1986 Who's Who by claiming that the Protector was an honorary Titan who became a member for busting a drug ring. While the Protector has made occasional background cameos over the years (most notably in a Titans Secret Files story and in the revised edition of Infinite Crisis), he is mostly regarded as an in-joke sort of character. According to George Perez, the original artwork of the Keebler issues was basically dabbed with white-out and re-inked in order to change Robin's panels.
In The Smurfs comic book series, Jeanty of "A Child Among The Smurfs" might have become this for Scruple from the cartoon show, in being a bratty child that becomes Gargamel's apprentice, but he ended up having a change of heart by the end of the story.
The Empowered series features The Maid Man, who (cross-dressing aside) is pretty much an Ersatz Batman. He's a Badass Normal who fights supervillainy using a variety of Maid-themed gadgets and Batman Gambits (relying on EMP to get captured while he's undercover with a team of Supervillains, so they can spring a surprise attack on them, for example). He also has a similar "code" and badass voice as the Dark Knight and is the one Hero that even the Supervillains seem to be genuinely intimidated by. In a nod to Frank Miller's increasingly insane take on the Batman Mythos, villains will usually refer to the character as "The Goddamn Maid Man!" whenever he shows up.
In Supurbia, a comic about the lives of the spouses and children of superheroes, the "Meta-Legion" is full of Ersatzes of the Justice League with a bit of Avengers thrown in:
Sovereign = Superman if he was gigantic asshole. To further the Superman analogy, Sovereign's "supporting cast" (girlfriends, enemies) all seem to have the initials "HH", must like the "LL" of Superman's cast.
Batu = Wonder Woman, only Mongolian and militant.
Cosmic Champion = Green Lantern
Night Fox = Batman (with some Iron Man and Doc Savage elements)... only he's in gay-love with his Robin/Nightwing analogue.
Big Daddy from Kick-Ass, is one of The Punisher, minus the skull. And tragic backstory, it turns out.
Dino Cop and the Spore are the DC versions of the Image Comics heroes Savage Dragon and Spawn respectively. In fact, Earth-41 is basically DC's version of Image Comics; there's also characters based on Superpatriot, Shadowhawk, and members of Youngblood. There's also some element of Composite Character — the one that looks like Badrock has a lot of the Martian Manhunter's physical traits as well.
The Thunderer of Earth-7 is based on Wundajin of Earth-8, making him one of The Mighty Thor as well. The differences in design between his world and that of Earth-8, and how the heroes of both worlds shared similar or identical codenames, suggested he was an "Ultimate" version, which was confirmed in The Just #1. Similar characters from Earth-7 include Crusader (UltimateCaptain America), Doc Future (Ultimate Mr Fantastic) and Golem (Ultimate The Thing). Strangely there also appears to be ersatz of non-Ultimate Marvel characters including Walküre (Angela who is from the main Marvel Universe) and Devilfist (Dark Horse's Hellboy).
Earth-34, Earth-35, and Earth-36 deserve special mention, in that each of them is loosely based on an already-ersatz-heavy universe (Astro City, Rob Liefeld’s Awesome Comics imprint, and Big Bang Comics, respectively). This means that, yes, they are populated by ersatz versions of characters who are ersatz versions of DC characters.
Earth-4 takes that a step further, casting the original Charlton characters as ersatz Watchmen.
Earth-39 is home to the Agents of W.O.N.D.E.R., who are very direct ersatz versions of the T.H.U.N.D.E.R. Agents — instead of Noman there's Nemo, instead of Raven there's Corvus, etc. DC actually had the rights to the THUNDER Agents a little over a year before Multiversity; one imagines that if they still did, this example wouldn't be here.
Solomon Grundy is often referred to as being DC's answer to the Incredible Hulk, though he predates Hulk by quite a while. He ended up gaining some of Hulk's characterization as time went on, including a variable personality and Hulk Speak. His appearances in Justice League played this up even further, with him being pursued by the military and gaining the Catch-Phrase "GRUNDY CRUSH!"
Noob. At some point, the Noob guild has to break a pirate named Jack Céparou out of a jail in which a dog-like creature is keeping the keys and help him find a treasure that turns out to be rhum. He shows up in a later comic looking for a lost compass.
The Invaders once fought the Scarlet Scarab, an Egyptian Captain Ersatz of the Dan Garrett Blue Beetle who became a Well-Intentioned Extremist when he allied with the Nazis against the British occupation. He gained his powers from a mystic scarab that was originally enchanted by an Egyption wizard called Garret to empower a warrior called Dann.
Everyone's"Stands" in the 1997 one-shot comic Diesel. Being a complete rip-off of the Stardust Crusaders arc of JoJo's Bizarre Adventure, it's not too hard to "base" your characters' stands on other anime and even American comics. The protagonist's stand is based heavily on both Hulk and Pitt, a 90's anti-hero, with wild hair similar to a super-Saiyan or Freakazoid!'s.
The indy book COPRA by Michael Fiffe riffs on Suicide Squad in the same way as Watchmen does the Charlton characters. The characters include Sonia Stone (Amanda Waller), Lloyd (Deadshot), Rax (Shade, the Changing Man), Lite (Dr Light), Gracie (a depowered Vixen) Guthie (Duchess) and so on.
In the Nikolai Dante story "The Romanov Job", Nikolai is pursued by Luther Emmannuel, a man who looks and acts exactly like Luther Arkwright; it's even mentioned that Arkwright is an alias of his. Nikolai also teams up with a group of master criminals, all of whom are based on other comic villains.
Grushko Creel is Crusher Creel, the Absorbing Man, enemy of The Mighty Thor.
In the "Amerika" storyline, the rebel leader is Major Victory, who is a recoloured Captain America.
Captain Action was an action figure in the sixties, whose gimmick was that he came with costumes of Superman, Batman, Spider-Man, Green Hornet, Phantom etc. He was relaunched with a comic from Moonstone in the 2000s, with a backstory where his suit enabled him to temporarily duplicate other heroes' powers and abilities. Unfortunately, Moonstone obviously didn't have the rights to the heroes whose costumes were used by the action figure (except Phantom), so he duplicates characters called Savior, Green Circle and so on.
The hero C.O.M.Bat of Plutona is described as "some rich guy in combat armor" and is an obvious invocation of Batman.
Superman once faced off against a hero from another universe named Captain Thunder who's only difference from Captain Marvel was a sun on his chest instead of a lightning bolt. His civilian identity was Willie Fawcett, so DC wasn't even trying to hide anything. Weirdly, this was published the year after DC started publishing a licenced Shazam! book, but until they owned the character outright they kept him separate from the DC Multiverse.