We all love aliens here. And so forth.

Antons:

The Antons are the inhabitants of the wandering planet Torsa, which spins out of space one day and takes up an orbit around the Earth. Soon the Antons are raining down on our planet in a full-fledged invasion, though it is never made clear if this has all been a series of cosmic coincidences leading to these two inhabited spheres being in such close proximity or if the Antons have employed the popular “mobile planet” method of interstellar travel. Whichever one it is is frankly secondary to the question of just how comic creator Steve Dahlman believed that a fast-moving planetoid in orbit would afflict the Earth with such high winds. It’s not just the effects of Torsa’s gravity on the atmosphere, because the winds seem to extend all the way into orbit. It’s a real mystery!

The Antons are cool looking hairy bean men with wings, warthog faces and those Colossus arms that everyone had in the 90s. As so frequently happens in Electro stories they briefly gain control of the Electro robot from Professor Zog, which serves to extent the lifespan of their invasion before they are all killed via robot fist. And lest you are concerned about that planet in Low Earth Orbit, Zog takes care of it by the simple expedient of blowing it up. (Marvel Mystery Comics v1 018, 1941)

Monsters:

“Monsters” is an unkind name for this species, who live in a cavern deep below the Atlantic Ocean and are so timid that the only reason we see even one of them is that he is under the mental sway of Shark foe the Mad-Man. Perhaps its for the best that they are left alone after the Mad-Man has his own brain removed as part of a scheme to transplant it into the Shark. (Amazing-Man Comics 010, 1940)

Monster-Men:

Though seeing these Uranian Monster-Men attack this human outpost and condemn its inhabitants to death on the icy surface of their world does cast them in a villainous light, we must take into account the fact that this is a comic from 1940 and as such colonialism is still seen as not only positive but as the natural and correct thing for a more developed people to do to a less developed one. These Earth men are there to take over Uranus and in their view the Monster-Men must adapt to this new reality or die. Perhaps they are enjoying the act of resistance more than might be palatable to us, but that does not make that resistance immoral.

Indeed, the story ends with hero Mars Mason using a Mercurian heat ray to raise the temperature of Uranus to Earth levels, thus dooming the native Monster-Men to a life at the planet’s poles. (Speed Comics 010, 1940)

Moon-Eyes:

Speaking of colonialist allegories, the Moon-Eyes are a species of nocturnal cavemen who live in one of the American lumber-producing regions and are being exploited by a camp foreman named Pierre who has discovered that they will work all night for a five-cent chocolate bar. Despite this amazing savings on payroll, Pierre is of course still whipping the Moon-Eyes and working them to exhaustion to extract the maximum amount of profit from them before they all expire from advanced tooth decay.

Though I must commend the Twister for stepping in to defend the Moon-Eyes and end their exploitation I must note that his ultimate solution, to seal them inside of their cave for all time, seems like a bit of an overstep. Is he of the opinion that the term “caveman” means “hominid adapted to live exclusively inside of caves?” Because those guys probably need to go outside for food, the Twister. (Blue Bolt v2 003, 1941)