Spore from Earth-41 seems to be a cross between Spawn and Swamp Thing.
Superdemon is what happens when you take the concept of Superman and add Etrigan into it.
Society of Super-Heroes: Conquerors of the Counter-World #1:
The Green Lantern of Earth-20 is Abin Sur with a costume heavily based on pre-New 52 Alan Scott's.
The Immortal Man of Earth-20 was once called Anthro, and his origin and powers are altered to be much more similar to those of Vandal Savage, who is now his alternate self from a Mirror Universe.
The Super-Sons in The Just #1 are Chris Kent and Damian Wayne, rather than Clark Kent Jr. and Bruce Wayne Jr. as it was Pre-Crisis.
In Thunderworld #1, Black Sivana of Earth-5 is a combination of two of Captain Marvel's deadliest foes: Dr. Sivana and Black Adam.
The Multiversity Guidebook #1:
Ben Boxer/BiOMAC of Earth-51 is a combination of Ben Boxer and O.M.A.C.. It's the Jack Kirby universe, OMAC had to come into it somehow...
Earth-32 is loosely based on the Batman: In Darkest Knight Elseworlds story in that its central premise is Bruce Wayne becoming Green Lantern in place of Hal Jordan, but expands it so that the other characters are also mash-ups of DC Comics characters rather than following the original story ending with that continuity's Superman, Wonder Woman and Flash becoming Green Lantern Corps recruits: WonderHawk, Aquaflash, BlackArrow... Subsequent stories set in this universe have added further composites:
The DC Year of the Villain: Lex Luthor oneshot has a scene set in this world where Luthor is standing in for Batman, in a Terry McGinnis style costume.
Flash Forward introduces Lightspeed, a composite of Linda Park (who in another multiverse was Dr. Light) and Godspeed. There is also a version of Red Hood and the Outlaws called the Outlaws of Justice, consisting of a Red Lantern Jason Todd, Starfire merged with Starro, Bizarro mashed up with Killer Croc, an amalgam of Donna Troy and Ravager and a fusion of the Creeper and Cheetah.
The 2019 series Dial H for Hero adds Ms. Super-Martian (Superboy & Miss Martian) and the villainous Harli-Quinnitor (Harley Quinn & the Anti-Monitor). We also see composites of Nightwing & Donna Troy, Starfire & Cyborg, Batgirl & Guy Gardner, Catwoman & Carol Ferris, Doctor Fate & Firestorm, and Plastic Man & Blue Beetle, among others. Miguel's counterpart is combined with Danny the Street, while Summer's counterpart is combined with Lobo.
The Green Lantern has the Green Lantern Batman taking down a gang boss called the Shark, who is a humanoid shark like the GL foe of the same name, but wears full evening dress and a monacle like the Penguin.
The Metal League of Earth-44 are a fusion of the Metal Men and the Justice League. Their leader, Doc Tornado, is a fusion of the Metal Men's Doc Magnus and Red Tornado.
The Justice Riders of Earth-18 are loosely based on the original Justice Riders comic about a Weird WestElseworld Justice League, but are given the names of DC's "regular" western characters. So Bat Lash is Batman, Johnny Thunder is the Flash, and so on.
In Mastermen #1, Blitzen, the femaleThe Flash of Earth-10, is briefly shown on one page to have blonde hair implying she’s an analogue of Barry Allen, but her costume seems to be based more on Jay Garrick.
Earth-11's Aquagirl from the Teen Justice one-shot is Jacqui Hyde, a Gender Flipped version of Jackson Hyde/Kaldur'ahm, the second Aqualad in the mainline continuity. However, her costume and hairstyle are taken from Mareena, the future Aquagirl first seen in Batman Beyond.
Several other Earth-11 characters are composites of the male characters they're meant to be the Gender-Bent Alternate Universe version of and the main universe's Distaff Counterpart of those characters. For instance, the Green Lantern counterpart is Star Sapphire (real name Carol Jordan), the Flash counterpart is Jesse Quick, and the Batman counterpart is Kate Kane as Batwoman (rather than "Brenda Wayne" or something).
