What ho! Aliens!
Martians:
These Martians attack Earth for reasons that will remain unclear forever, because the story they appear in never actually gets an ending. In fact, they never even show their faces, instead attacking from their very cool-looking ships and sending their very cool-looking robots to act as ground troops. The initial invasion is driven off by superhuman scientist Greg Gilday and his associate Joan and then the Martians just never bother to return for another shot. (War Comics 002, 1940)
Barrangees:
After their initial encounter with the giant insect life of Planet Barrang, Captain Tornado and his companions end up falling in with the Barrangees, a humanoid species who were forced underground when the insects began to increase in size and intelligence, and despite the common cause that they had made with the purple ant faction, the trio are far more comfortable around an non-insectoid race.
(wildly, this extends to not even questioning the Barrangee caste system in which servants are surgically rendered mute as a symbol of their subservience and children are raised in total darkness to give them enhanced night vision)
The Earth-people quickly resolve to help the Barrangees return to surface life using their knowledge of firearms and insecticides. Their main obstacle to this, other than the insects themselves, is the Barrangee High Priest, leader of a religion that worships the Sacred Centipede and by extension all of Barrang's insect life. Captain Tornado eventually resolves this by shooting both the High Priest and the Sacred Centipede dead. (Popular Comics 048, 1940)
the Batmen:
The Rocket and the Queen of Diamonds seem to run into another hostile humanoid species every time they leave the walls of the hidden Diamond Empire, and the Batmen are yet another of these, which they end up in the clutches of after crashing the Rocket's ship into an underground cavern. The king of the Batmen is of course a creep who lusts after the Queen and attempts to dispose of the Rocket via gladiatorial combat vs a giant turtle, but once the Rocket learns that the Batmen are mortally afraid of fire it's all over. Quite literally, because he accidentally burns down their city. (Pep Comics 003, 1940)
the Batmen of Kordano:
It's been a while since I read "Air-Sub DX" and the world-building was never its main focus, so forgive me if I'm wrong, but as I recall it was set in an undefined future on a planet that I have written down as "Tago-Lor" but could have just as easily been a far-future Earth. The crew of the titular Air-Sub contend with the machinations of various bald guys, including Klawger here, who has assumed the identity of the administrator of some sort of mining colony.
All this is to say that I have no idea what the deal is with the Batmen of Kordano, aka the Living Dead Men, aside from the facts that a. they look cool, b. they have two great names, and c. they ride around in squat cylindrical vehicles called "mobile pillboxes," which is fun. Aside from that, no idea. Why so aggro? Where or who or what is Kordano? No idea. (Amazing Mystery Funnies v2 005, 1939)
