Here's my review of yet another massing of monsters in the TV movie SCOOBY DOO AND THE RELUCTANT WEREWOLF. The only monsters close enough to their original models to make this a crossover as well as a mashup are Dracula, the Frankenstein Monster and his bride, and Mister Hyde, despite the latter getting the punny name of "Mister Snide."
One of the earliest crossovers of TV cartoons appeared after the 1968 success of THE ARCHIE SHOW, for in the succeeding year, Filmation adapted the SABRINA comic series. But while the comic series had never been tied to the Riverdale Universe, the first year of THE SABRINA COMEDY SHOW was tied to the Archieverse from the first. SABRINA in turn birthed "The Groovy Goolies," who also got their own series (unfortunately).
Thus, as soon as the comic-book Sabrina got her own self-titled feature in 1971, Sabrina immediately melded with the Archie characters and remained so in most later iterations.
I may have found the most obscure monster-mash ever in the barely watchable kid's film WITCHMAS, reviewed here.
I've reviewed SCOOBY DOO: RETURN TO ZOMBIE ISLAND here. In addition to its primary purpose, to "retcon" the events of the 1998 movie SCOOBY DOO ON ZOMBIE ISLAND, it also throws in a prologue where the intrepid teens capture a whole family of malcontents who dress up like phony monsters. Three of these look like familiar Scooby Gang antagonists-- the Creeper, the Snow Ghost, and the Spooky Space Kook. However, since there's not even a faint tie to the original crooks, there's no crossover here.
The folks at Riffteax, in their quest for inspired garbage to mock, helped bring back into currency a near-plotless half-hour short called SANTA'S ENCHANTED VILLAGE. It was shot at two related Christmas theme parks in California and in Illinois and produced by K. Gordon Murray, famous for doing a lot of sixties kiddie features as well as for dubbing numerous Mexican fantasy-films for American audiences. In addition to Santa Claus, the legendary characters include Merlin and Puss in Boots. Far less well known are "the Ferocious Wolf" and "Stinky the Skunk," who are doppelgangers of characters from some of those Mexican films, the best known being TOM THUMB AND RED RIDING HOOD. But since the skunk and the wolf aren't connected to those characters-- indeed, the actors' costumes only resemble the Mexican depictions in a general way-- I wouldn't say that these two anthropomorphics are crossovers as such.
ADDENDUM: I may as well note that Merlin also appears in the Mexican film SANTA CLAUS from 1959, so that's why Murray stuck the Arthurian wizard in with the jolly old elf. Though I didn't mention Merlin's presence in my review, I would consider the film a crossover for that reason. But I *don't* consider the appearance of a minor devil in the same film as constituting a crossover, because it's not THE Devil.
The TV cartoon "Mother Goose Land" has Casper try to prevent his supporting ghouls The Ghostly Trio from raising havoc in Mother Goose Land. They encounter Little Bo Peep, Little Boy Blue, Little Miss Muffet (whole lotta littles), Jack and Jill, the Mouse and the Clock It Ran Up, Jack Be Nimble, the Dish and the Spoon, Humpty Dumpty, and both Mother Goose and her bird. Casper brings in Wendy the Good Little Witch to help drive off the Trio.
In "Ghost of Honor," another cartoon collected alongside this one on YouTube, Casper visits the Paramount studios to see how cartoons are made. There he encounters various Paramount cartoon characters who come to life off the paper, though the only one I recognized was Baby Huey.
Of the "Mother Goose" characters who actually appear with Betty, as opposed to just being mentioned, I count Humpty Dumpty, Old King Cole and his Fiddlers Three, Little Boy Blue, The Pied Piper and the Mice of Hamelin, Little Miss Muffet and her spider, the Old Woman Who Lived in a Shoe, the cast of the "Cow Jumped Over the Moon," The Three Blind Mice, and the Four and Twenty Blackbirds, who beat up Muffet's spider.
Until today I'd never noticed that Warners' character Henery Hawk had actually starred in his own 1942 cartoon before becoming a support-character in the 1946 debut cartoon for Foghorn Leghorn, WALKY TALKY HAWKY. So HAWKY is a crossover in which a former Prime gets permanently demoted to the status of a Sub.
The 1995 theatrical cartoon SUPERIOR DUCK, in addition to squeezing in a bunch of Warners cartoon characters into its scattershot plot, also includes an appearance by Superman, looking a little like the Joe Shuster version.
Two more null-crossovers in which an established villain appeared with a newbie, but the newbie failed to become a recurring figure from then on.
First, from 1950, The Catwoman and one-shot gang-boss Mister X"
Like the previous entry CARRY ON SCREAMING, the 1953 Dennis Wheatley novel TO THE DEVIL A DAUGHTER, reviewed here, stands as a "reference only" crossover, in that it's stated that the events of a different Wheatley novel, starring different characters, took place in the same universe of the characters of DAUGHTER. But since there's no interaction of icons within the two literary worlds, it's a null-crossover.
One of the earliest, if not the earliest, teamup of Superman villains, "Superman's Super-Magic Show," appeared in ACTION COMICS #151 (1950). Lex Luthor has to put his usual ruthlessness aside to gain the help of Mister Mxyzptlk (and, to a lesser extent, The Prankster) in a project to confound the Man of Steel.
