I have certain theories about Toobworld that must be taken on faith. The premise might never have been seen - at least in the provice of Earth Prime-Time's dimension - but we have seen suggestive proof of their existence reflected elsewhere with other characters or locations.
Here then is my Super Six List of people, places, and things which probably exist(ed) in Toobworld, but we just haven't had confirmation yet.....
This may not be the actual name for the organization, but such a group would be responsible for masking the truth about people like James Bond, the agents of U.N.C.L.E., and the Time Lord known as the Doctor by creating TV shows, movies, comic books, etc. to convince the general populace of Toobworld that they are fictional. This would be a boon in splainin away the Zonks so often created by mentions of those characters and others like them.
Middle-Earth exists in BookWorld, the Cineverse, and the Tooniverse; it's even suggested to exist in Skitlandia. But it has yet to become more than fiction in Earth Prime-Time. But I may have found a theoretical suggestion of its existence in the Age of Legend - thanks to a foreign country visited in an episode of 'It Takes A Thief'!
3] Dr. Moreau
The mad scientist who brought human intelligence to the animals which only brought them misery was originally from BookWorld. He has been seen several times in dimensions of the Cineverse, and in the Comic Book world as well as in the Tooniverse. But as for Toobworld? Although it can't be proven, Dr. Moreau has to be the reason why Gomez Addams' silent business partner was a tux-wearing giraffe.......
4] Sam Spade
Another citizen of BookWorld and the Cineverse. I'm shocked - shocked! (Sorry, wrong Bogie reference) - that there never was a televersion back in the fifties when movie adaptations were common on TV. But thanks to episodes of 'Honey West' and 'Fantasy Island', we may have seen replicas of the Maltese Falcon, at least. Maybe.
5] The Coneheads of Remulac
Originally seen in the Toobworld dimension of Skitlandia, they've also taken on new lives in the Tooniverse and in the Cineverse. Technically they exist in BookWorld as well with a movie tie-in book. They would have been perfect for televersions back in the prime of Dan Ayckroyd and Jane Curtin (with Laraine Newman taking on a new role as she did in the movie), but it was not to be.
Still, I believe we have seen another Remulac inhabitant - well, at least the half-breed son of one - in Gotham City, who can provide ties to 'The X-Files' and to real world Russian history.....
6] The Justice League Of America
Superman, Wonder Woman, and the Dynamic Duo of Batman and Robin never crossed paths in Earth Prime-Time, at least not as seen by the audience of the Trueniverse. They have been comrades in arms in the Comic Book World and in the Tooniverse. And soon enough at least the Big Three (minus the Boy Wonder) will be reunited in the Cineverse.
But as for Earth Prime-Time? 'The Adventures Of Superman' ran from 1952 to 1958. 'Batman' was on the air from 1966 to 1968. And although 'Wonder Woman' overlapped them both because she had adventures during World War II and then seen again in the mid 1970s, her show was broadcast from 1975 to 1978, past any possible involvement with the other two shows. (Especially considering the death of George Reeves......)
Within the "reality" of Toobworld, however, Superman's adventures continued until the early 1960s when he died from Kryptonite poisoning. (An accepted theory for Toobworld Central) And Batman didn't just start his career as a caped crusader in Gotham City in 1966; he had to have been fighting the good fight for several years before that. And as previously mentioned, because of her near immortality, Wonder Woman would have been around to team up with both of them.
[There's another version of this picture on the web, but it includes the Flash. However, his orgin as the Scarlet Speedster didn't happen until 1990.]
So far these examples haven't been confirmed to exist in the main Toobworld, but it's pozz'ble, just pozz'ble that one day they will be. It may be a long shot, but it has happened before: Until the talking horses of Houyhnhnm trotted out of BookWorld and into Toobworld thanks to a mini-series, I had no way to back up my claim that 'Mr. Ed' came from that same island to be found in Jonathan Swift's "Gulliver's Travels".
And how did Mr. Ed get away from his island home and to America, you might ask?
Take that, "neigh"-sayers!