We got Fish-Men, we got Fishmen, we got other kinds of men.
Fishmen:
Adventurer Lance Rand has acquired a map showing the location of the sunken continent of Atlantis and so naturally he sets out to see if it's accurate and more importantly to find out if there's any ancient Atlantean treasure there for him to loot. Making his way to the ocean floor, Lance and his pal Tubby are almost immediately accosted by a Fishman riding on a sea monster. This is a good sign!
The sunken city of Atlantis does indeed turn out to me right where the map said it was, complete with some monumental bare-assed statuary. Lance and Tubby are able to drive their submarine tractor right up to the base of what must have been an important Atlantean idol and pry the disco ball-sized diamond out of its forehead, upon which they have to deal with another squad of hostile Fishmen. Though the implication is of course that these fellows are the descendants of drowned Atlantis, the fact that they never say anything really makes it hard to confirm. Perhaps they are unrelated underwater humanoids who just disapprove of Lance and Tubby's wanton looting. Whichever it is, I really dig the little wing-fins that grow out of their backs. (Cat-Man Comics 001, 1941)
Fish-Men:
When oceanic adventurer Navy Jones' submarine is lost at sea, he is rescued by an undersea race of aquatic humanoids who don't really have an official name but who are more often than not called Fish-Men or something similar. Despite some early conflict engineered by the scheming Prime Minister, Jones soon becomes the Fish-Men's champion.
Fish-Men society is ruled over by a more humanoid nobility, represented here in the forms of their unnamed king and his daughter/ Navy Jones' love interest, Princess Coral. As usual, the reasons for these morphological differences are not explained and likely boil down to "we didn't want our hero to be romantically involved with a fish."
Like many Fiction House heroes, Navy Jones passed through a lot of hands over the course of his career, and the Fish-Men had a correspondingly large number of looks, each of them charming in its own way.(Science Comics 001, 1940)
Fishmen:
This Fishman is encountered by Tabu, Wizard of the Jungle in what is probably a prehistoric underground enclave that a group of explorers stumble across "far to the Southeast of the Congo". I say probably because Tabu gasses on about how they have gone back in time, which might be meant literally and might just be a bit of excessively flowery exposition.
The above is virtually all of the on-panel time that the Fishmen get, as the narrative is much more focused on the drama of one of the explorers falling in love with a cave woman. (Jungle Comics 011, 1940)
Flame-Men:
Just as Rex Dexter of Mars and his companion Cynde are about to leave the planet Nexis and its friendly inhabitants, the Nexis as part of their never-ending attempt to reach Mars, the world is attacked by some sort of apocalyptic flame weapon.
Rocketing into space to investigate, Rex and Cynde discover that the source of the attack is a fiery comet that is being directed by a massive spacecraft, by which they are swiftly captured. Inside they find the Flame-Men from Planet Emalf, who are attacking Nexis as the first move in their attempt to destroy the rest of the universe. Why are they doing this? No idea.
The Flame-Men are unprepared for Rex's freeze-ray gun, and shrivel up into little burnt matchstick men in a way that is as aesthetically pleasing as it is unsettling. (Mystery Men Comics 010, 1940)
Categorized under: Aliens, Animals (Fish), Elements (Fire), Generica (Men)
