We've met a few of them in the past, but here's another dose of the inhabitants of the Fourth Dimension, as explored by Flip Falcon.
Zezo:
Zezo works for the Fourth Dimensional villain Lucifer as a guardian. We don't learn too much about this fellow - is he a one-off or representative of a whole species, for example - but I like his moxie and his big teeth. (Fantastic Comics 015, 1941)
Koggo:
Koggo is an even more mysterious fellow than Zezo, given that he is more obviously the product of a civilization of some sort: he has clothing and weapons and hypodermics full of Agony Serum, and also a conceptual framework that allows him to believe that human pilots are somehow trying to invade the Fourth Dimension. This leads him to kill and kidnap several of them until he is stopped when he is exploded by Flip Falcon. (Fantastic Comics 018, 1941)
Fourth Dimensional Dragons:
Fourth Dimensional dragons have a body plan that is a variation of the modern fantasy concept of the wyvern, with wings and front limbs appended to a long serpentine body. It's unclear just how intelligent they are: Robbo here acts like an animal, but he also has a name. (Fantastic Comics 015, 1941)
Serpo (Poison Dragon of the Elements) also has a name, but given his seeming status as more of a natural disaster than an inhabitant of the Fourth Dimension, that might just be equivalent to when we name hurricanes. Intriguingly, Serpo is able to cross the dimensional boundaries under his own power.
Serpo comes to the attention of Flip Falcon after he abducts a woman from Earth and learns too late that he is susceptible to being exploded. (Fantastic Comics 016, 1941)
Demi-Things:
Any time you talk about Flip Falcon and the Fourth Dimension, you're going to get Demi-Things coming up. The first time this occurs is when Gogo, Master of the Demi-Things attempts to abduct the same woman who had already been snatched by Serpo. And just like Serpo, Gogo is unprepared for the explosive power of Flip's dimensional energy. (Fantastic Comics 016, 1941)
The death of Gogo opens the way for Kandor to become Lord of the Demi-Things, and while we have no indication of whether he is a more benevolent ruler than his predecessor, he certainly is aware of the fact that he rules at Flip Falcon's whim. Or perhaps they really are friends, who knows. (Fantastic Comics 018, 1941)
Finally, we have Zorka, the Giant Demi-Thing. Zorka guards a region of the Fourth Dimension containing the element "acco-nito." Why? This is not explained - perhaps it's just a classic case of treasure-hoarding. In any case, Flip needs so acco-nito to save a woman's life, so Zorka gets exploded.(Fantastic Comics 019, 1941)
Octopus Men:
Strictly speaking, the Octopus Men are not Fourth Dimensional beings, instead, they are the inhabitants of the wandering planet Octo, which up and wanders straight through the dimensional barrier one day and allows the Octopus Men to start beating ten kinds of hell out of the Demi-Things.
Despite this, the Octopus Men prove just as vulnerable to being exploded as all of Flip's other enemies, which he discovers after intervening to prevent the conquered Demi-Things from being impressed into a life of space piracy by the Octopus Men's boss, a human man named Otho. Just how he came to be on an extrasolar planet in the first place, let alone in charge of the place, is left unexplored, but since Flip drags him back to Earth to stand trial we must assume that that's where he started out. I have no idea what Flip thinks that the charges might be, by the way. (Fantastic Comics 017, 1941)
Unnamed Species:
This unnamed fellow is remarkable mostly for being the antagonist of Flip Falcon's final adventure. He seems to live on a planetoid by himself, has captured space explorer Irwin Burns and demands help in his plan to go to Earth and kidnap a woman (he needs a "queen" and can't be bothered to date).
As befits the final Flip Falcon villain, this fellow gets exploded. It's a real shame that this is our last look at the Fourth Dimension as the cosmology was getting very weird: it's another dimension but also Hell and/or Purgatory and it connects to all space and time and as a result of this you can just kind of pass from our dimension to it by travelling far enough out into space? I mean, talk about a rich setting for cosmic horror. (Fantastic Comics 021, 1941)


























































