Rad Omeron: 1938, Cocomalt Big Book of Comics #1 (Chesler). A Martian bandit and interstellar bandit, he kidnaps Dr. Carter's daughter Gloria in hopes to hold off the officials and get free reign on plundering. However, he's tracked and possibly killed when blasted by a ray gun by Dan Hastings. NOTE: This is an oddity of a book. Various features seem to indicate it's a continuation of Centaur's Star Comics, the GCD lists it as a Quality book, but the mag and features claim that it's copyrighted by Harry "A" Chesler syndicate and includes characters like Boodini, Dan Hastings, Lucky Coyne who all appeared in books by Centaur, MLJ and later Chesler's own line. The book otherwise seems to be a product of sponsorship by Cocomalt and early vaudeville, radio and animated (!) star Joe Penner.
Radion: 1940, Green Mask Comics 3 (Fox). Foe of the Green Mask and Domino.
The Rajah: 1940, Wham Comics 2. (Centaur). The Rajah, a Hindu, is known for his mastery of black magic. A pair of crooks, the leader being Blacky Dooley, get him to help them kidnap Craig Carter's girlfriend and getting Carter's magic ring as ransom. Carter calls on Pluto, god of black magic to help him. The Rajah is indeed very powerful and manages to give Pluto a good battle for a little bit before being defeated. It's unclear whether Pluto killed him, but being the god of death...
Rajah of Destruction: 1942, Cat-man Comics #15/16 (Holyoke). Fatman in a turban, appeared in the last panel of the Cat-man story in #15 setting the stage for the story of #16.
Rajo: 1946, Sparkling Stars (Holyoke). Large barrel chested pirate, bald but with a beard and an eye-patch. He and his men came to the jungles and conquered one kingdom and set their eyes on a neighboring one ruled by the cruel Maata, the leopard girl whom Rajo wants as his mate. Opposing their plans of conquest and raiding are Fangs, the wolf boy and his pack of loyal wolves.
Ramun: aka The Evil One. Ramun is a Far-Eastern magician and foe of Marvelo. He has a small trained ape named Edpo whose talents include throwing knives.
Rand, Barton: 1943, Heroic Comics 19 (Eastern Color Printing). The head of an Axis sabotage ring in Louisiana that blew up American ships in the Gulf of Mexico. He posed as a genial sportsman in order to know which ships to target. He was captured by Man O'Metal.
Rango: 1940, Green Giant #1 (Pelican). Failing to conquer Europe, this bald mastermind retreats to his laboratory in Slavonia. He creates a drug that turns him into a giant as tall and mighty as multi-storied buildings. Creating havoc and destroying several cities, he wades into the Atlantic to make his way to the U.S. However, by this time Master Mystic in his arctic tower is aware of him and speeds to meet him. After a furious battle, Rango is defeated when the Master Mystic unleashes his mental "liquifying rays" which strike Rango in the head and penetrate to his brain where he promptly melts as if made of wax.
Trigger Ratsel: 1942, Green Hornet Comics #7 (Harvey). A gangster whose gang is leaning on food and milk truck drivers for protection money. He has the honor of being the first man to be brought to justice by the modern Robin Hood and his men.
Comrade Ratski: Speed Comics 10 (Harvey). In a hollowed out mountain peak lair in the Rocky Mountains, Comrade Ratski holds 3 scientists prisoner and forces them to create devices for his use. They create an earthquake machine and a formula to enlarge insects to the size of an ox. He is stopped and the scientists are rescued by Shock Gibson. However, Ratski does escape, I don't know if he returned to bedevil Shock Gibson.
Racker: Exciting Comics15. (Standard) This fiendish man used to be a scientist before turning his mind to evil. He kidnaps scientists and through various torture and death devices, forces them to sign over ownership to their inventions before they will conveniently disappear. He and his gang are captured by the Black Terror and Tim.
Rasnel: 1942, Planet Comics #16 (Fiction). In the year 2541, Rasnel is the lord of the planetoid Zaten who dreams of conquest, torture and beautiful women. Even with the aid of his bullet-hooded flying men, he finds Earth a tough nut to crack as it's under the protection of the immensely powerful Red Comet.
Rassimoff: Popular Comics (Dell). Rassimoff is a spy for the country Urasia which is waging war on the neighboring peaceful country of Novoslavia. Dr. Hormone's plucky grand-daughter slipped him a potion containing donkey hormones which has given him donkey ears as well as massive strength of the beast of burden, after which he's called Assinoff.
Rasputin, Jr: 1944, Cat-Man Comics #25 (Holyoke). Rasputin Jr is a hypnotist who puts on shows. His main bit is showing that hypnosis cannot force people to do something that offends them morally. He picks a girl out of the audience and hypnotizes her and then hypnotizes her friend, having her friend first stab her in the back with a cardboard knife and then showing the person wouldn't do it with a real knife. Rasputin is also with a gang of crooks and seeing the Deacon as part of the audience, the Deacon is recognized as being a former great safe-cracker. The banker's daughter is hypnotized into guiding the crooks into a bank (where they kill a guard) and a hypnotized Deacon is ordered to crack the bank vault. The Deacon struggles mentally against the command. Mickey had shadowed the Deacon and picks up a gun and blasts the crooks, killing Rasputin and breaking the hypnotic hold.
Rats: 1948, Airboy Comics (Hillman). Rats with human level intelligence attempt to take over the world and even enlisting the aid of bats as their air force (think of Hitchcock's The Birds only turn them into rats and grant the viewer insight to their conversations and plans). They are opposed and thwarted by Airboy in both of their attempts.
Ratzo: February 1943, Clue Comics #2 (Hillman). Ronald Byrd contributes: The rodent-faced Ratzo leads a gang of criminals who use purple fumes to paralyze their victims. He and his gang are brought to justice by Stupid Manny.
Red Gang: 1942, Amazing-Man Comics #26 (Centaur). A gang of crooks that came up with some goggles that allow them to see into the King of Darkness' blackout rays. He still managed to take out the gang.
The Red Hood Gang: 1937, Funny Pictures Stories #3 (Centaur). A gang of men in suits and red hoods that cover their heads are behind a series of clever unsolved murders. However, the news stories of Red Dolan, gangbuster, has been drawing attention towards them so they kidnap him. His cleverness allows him to capture the whole gang and deliver them to the authorities.
Red Lash: 1943, Cat-man Comics #19 (Temerson/Helnit/Continental). A Nazi agent hiding out in the swamp, the Red Lash has two long red two-pronged whips attached to the ends of each arm and he uses them to torture secrets out of military men. He's captured by the Hood. By appearances, it would seem that the Red Lash's arms are amputated at the wrist where the whips are attached. But, given the limitations of the artwork that may or may not be the case. No origin is given to him. He may also be a Russian as he's called a "Tartar" in the opening splash page, but no other such reference is given.
Red Raider I: 1936, Funny Picture Stories v1n2 (Comics Magazine Company/Centaur). In the mid-East (possibly India), Hillman Rango Osef is called the Red Raider because of his red beard. He leads an army of 100 ruffians on raids against various towns and is feared that he could raise 500 more. He's captured by Lt. "Smoky" Battle and his Gurkha soldiers (specifically, it's one of Battle's men, Shabu, who physically captures a wounded Rango Osef).
Red Raider II: 1940, Keen Detective Comics #21 (Centaur). A submarine captain of an un-named country goes nuts and through his mania is able to hypnotically control his crew. He starts attacking all ships, even those of his own country. Eventually, he paints his sub, calling it the Red Raider and takes down his country's flag and replaces it with the black and white skull and crossbones of pirates. The captain dresses in red sea captain's garb. Captured by the Masked Marvel. Note: Red Raider I is also a Centaur character.
Red Regent: 1942, Thrilling Comics #2 (Standard). Red Regent was once a laborer in Germany. A chain hoist knocked him into a blast furnace. Instead of dying, he emerged with the asbesto suit bonded to his body and containing 1700 degrees of flaming heat. Hitler sends him to America as an agent however, he has no loyalty for his country. Instead, he seeks out American criminal Matt Madden to team up with. Stopped by Captain Future, though he escapes while Madden is killed in an explosive car wreck. The Red Regent's super-heated body melted bullets and steel on contact, although he presumably had some control over his powers as he didn't set everything on fire around him.
The Red Scorpion: 1943, Heroic Comics #17 (Eastern Color Pringing). The Red Scorpion is a gang leader that has his hands in many pies. He doesn't wear a costume but has taken the code-name. Whenever he has a rival bumped off, the gangster bears an ink mark on his body of a tiny red scorpion. The villain kidnaps Joyce, friend of Hydroman, as Hydr crime fighting activities are bad for business. Instead, this only puts him on his trail as he'd never heard of the Red Scorpion before (although that whiz kid Rainbow Boy has). The bug-eyed face of the villain turns out to be a mask, that he's in reality Barney, an owner of a nightclub who was suspected as to having underworld ties as well as being an associate of the Scorpion. NOTE: At this point in time, the Hydroman stories often ended with a panel or two leading into the next adventure. As these were often a tease, and not actually showing the criminal on the page (though it would sometimes give his name), I'm listing the comic that actually has the story as the first appearance.
Redbeard: (No publishing info). Dennis Durrant tells me: Redbeard was a pirate who sailed the seas in the Sixteenth Century. Four centuries later, after several ships appear to have been robbed by Redbeard's pirates, Dr. Strange is sent to investigate the theft of a map leading to Redbeard's treasure. After apprehending two men who had been sent to kill him on board a ship that is sailing to Panama, the doctor goes to a party on the nobleman Lupesco's galleon, only to be taken prisoner when Lupesco orders the galleon's crew to set sail. He is taking them toward a rendezvous with a German submarine to which he transfers his prisoners, after which both vessels sail for Redbeard's Island and the prison there, where he holds his party guests captive. Dr. Strange stops him and frees the prisoners, then blows up the island with a torpedo he has captured when they have set sail. He later learns that Redbeard's real name was Lupesco, and that the current Lupesco was his descendant, who wanted to carry on the family tradition.
Relley: 1945, America's Best Comics 116 (Standard). A known and oft convicted fifth columnist and black marketeer. He took to wearing a hood and robe to hide his identity from the men who worked for him. He was stopped by the Black Terror.
Retlih: 1944, All Top Comics #nn (Fox). In a cave somewhere in the Arctic lies a city called Underacia. It was founded by an American explorer at some point in the past. Lost, he taught the natives to farm and Democracy and they built a fine city. Then came a petty man calling himself Retlih. He killed their leader and set himself up as king and tyrant. He's not simply a stand-in for Hitler as was sometimes wont in those days, the hero Red Robbins actually calls him a "regular little Hitler", so the name of Retlih is presumably a deliberate choice by the villain. Red restores communication and calls in the Marines to deal with the portly little dictator and his storm troopers. In this story, Red has no powers.
Rhang: 1941, Bang-Up Comics #1 (Progressive). Middle-Eastern villain. He spent three years in prison at Senegal for Ivory poaching thanks to Jeff Barter. He escaped and started dealing in slaves with the help of some of the more merciless tribes.
Rikor: 1941, Stars and Stripes #4 (Centaur). Anthony Durrant writes: Rikor was a member of a group of German spies who killed the Union leaders of an unnamed American city and took their places, forcing the union members to sabotage their workplaces by threatening to harm their wives and children Three concentration camp escapees named Pepper, Van and Whitey - Pepper and Van were framed on false charges, and Whitey killed a German soldier who was beating a little crippled girl - have formed a team called the Stars and Stripes, swearing an oath in their own blood that they will protect America and clean out all the enemy spies, and the three of them put a stop to Rikor's evil plot. This task is made especially difficult because Rikor and his gang control the Union's enforcers and the Stars and Stripes have to fight them off in order to capture the spies.
The Ripper: (Harry "A" Chesler) The Ripper is a "swamp rat" and along with his loyal gang, does jobs of sabotage and such for Hitler in exchange of being made leader when he invades America. He and his gang are undone by the brave boy hero, Johnny Rebel and old family servant, Rufus.
The Riverdale Killer: 1941, Thrilling Comics #8 (Better). A hooded killer stalks the halls of a Riverdale Mansion, killing first Frank Parsons. Peggy Allen (aka the Woman in Red) is sent to investigate and prevent more killings. Henry and Violet Parsons, along with their butler are supposedly the only ones there, but Peggy realizes the family has a secret. When Henry is also killed, she discovers that the family keeps an insane brother locked away. The Woman in Red exposes the killer as none other than Violet, who had hoped to frame her brother for the killings, his insanity nothing more than a frame-up itself after he had suffered a nervous breakdown years ago. Violet had hoped to inherit the family fortunes once her brothers were out of the way.
Robbing Hood: 1944, Prize Comics #39 (Prize): Anthony Durrant provides: Robbing Hood lived out the Robin Hood legend in reverse, stealing from the "decadent" poor to give to the "unfortunate" rich people. He was apprehended by Airmale and Stampy after getting himself caught inside a chimney on his way to play Santa Claus for another rich person! Robbing Hood was an expert archer.
Robot: 1939, Amazing Mystery Funnies v2 #11 (Centaur). Don't know if he appeared in the story, but he was getting the worse of it on the cover by the Fantom of the Fair.
Robot Pyroman: 1946, Startling Comics#37 (Standard). For some reason, he's in the splash page but not in the story or cover. But, he looks just too cool to pass up.
Robot Terror: 1941, Miracle Comics #4 (Hillman). Most of the world believes mad scientist Howland to be dead, but he's not only alive but he's built the marauding Robot Terrors: about 8-foot tall robots that are bulletproof, strong enough to stop a car dead and can fly via a small propellor on the tops of their heads. The Sky Wizard uses Howland's own microphone to command them to attack each other. When Howland tries to intervene they choke him.
Robotmaster: 1946, Exciting Comics #45 (Standard). This mad scientist had a remote controlled robot. Only appeared on the cover but was kinda cool looking.
Rocko: Planet Comics #5 (Fiction House). Foe of Space Admiral Curry.
Rodent: Boy Comics 15 (Lev Gleason). A ratty faced muscular foe of the boy hero Crimebuster.
Rogats, Erick: 1941, Stars & Stripes #3 (Centaur). A foreign agent and scientist, Rogats operates out of an abandoned castle with his servant Argo, whose malformed, scarred and tusked face is kept obscured by a hooded robe. Rogats is after Professor Taft's petrifying formula and sends Argo to kidnap the professor and bring back the formula. However, Argo is followed by the hero the Black Panther. Argo is accidentally injected with the formula and possibly dies. Rogats flees from the Black Panther by attempting to scale the castle tower, but he slips and falls into a black quick-sand mire at the base of the castle and presumably dies. The castle is some set-up, it's by a cliff in the woods near an unnamed town. It has a secret entrance via a tunnel at the base of the cliff for vehicles. Inside Rogats has equipped a large laboratory with every known scientific device known.
Phil Rogers: 1941, Captain Aero #1 (Holyoke). Rogers is secretly a devoted Nazi spy leader and wears a hood to help protect his identity as well as a long blue coat or robe over his clothes. He has befriended Professor Andrews and daughter Linda. After Andrews invents a super-bomb, he decides on a vacation at the home of Rogers. Unfortunately for Rogers, the hero Solar worms himself in on the vacation. Rogers and his gang are uncovered and captured, no match for Solar's magic and invisibility. Masked, he's visually interesting and his insisting on saluting a picture of Hitler before starting business marks him a little different than your average sympathizer. However, he doesn't take a code-name to go with his flamboyant look and he's really out of his element fighting Solar.
Rokula: 1941, Silver Streak Comics #7 (Lev Gleason). Rokula keeps a base full of scientific marvels including machines that allow him to hypnotize others which he uses to make kidnapped scientists create stuff to help him become ruler of the universe. Stopped by Zongar
Role: 1942, Super-Mystery Comics v2#6 (Ace). Billing himself as Role, the Man of a Thousand Faces, he used his talents to rob banks of their gold but leaving the money. To help counter pursuit by cops or superheroes such as Vulcan, he had a gun with that emitted typhoon like winds, strong enough to blow out Vulcan's flames and even lift him into the air and deposit him blocks away. His disguises included a blind man, a technician, bank manager and even a bank president where he fooled the man's own daughter. Vulcan tracks him to the factory where the typhoon cars are built where he discovers American gangsters posing as Nazis. What the gangsters don't realize is that Role is really working for Germany and shipping the gold there. When it looked like his capture was a foregone conclusion, he shot himself through the head. When his mask was removed, he was found to actually have a grey skull-like face underneath, confirming his admission at the beginning of the story that he had no face.
Rook: 1941, Mystery Men Comics (Fox). This bug-eyed villain had a flashlight-like weapon that cast a hypnotic ray. He seemed to be in the employ of a Sonya Voska. While he was opposed by the mystery man Lynx, he apparently also had earned the enmity of a gangster called Baldy Burke.
The Rook II: 1946, Black Cat #2 (Harvey). The Rook is a chess expert who has organized a "Chamber of Commerce" for criminals and racketeers, to stamp out those that oppose their rackets. First order of business is to exterminate the Black Cat and to do that he must find out who she is. He runs an ad for any information and clues. However, the criminals aren't exactly the smartes or even the most literate of men. However, it also serves to bring her and Rick Horne to them where they are captured. They escapeescape and round them up. The Rook has a mania for chess, and has his hideout in a castle. In addition to the various rackets and gangsters he's organizing, he has his own men that are dressed up as chess pieces and a checkerboard pattern on the floor that conceals trap doors from which he can "checkmate" his foes. Why he calls himself "the Rook" instead of "the King" not sure but he sits at the head of this board in a throne. He apparently escapes soon after as in a text story in the same issue, he is killing rival players during a chess tournament. He's revealed as being player "James Mason".
Roscoe, Violet: Jumbo Comics (Fiction). Anthony Durrant writes: Violet Roscoe was a vicious gangster and murderess who left the scent of her violet perfume on her victims' bodies. After she was hanged on testimony provided by Agent ZX-5, she appeared to come back from the dead when she killed the judge who had presided over her trial, and later a prison guard who had seen the murderer tear Violet Roscoe's dress in the prison morgue was murdered as well. Making it look like the judge had survived the murder attempt, ZX-5 hid out in the bed in the hospital room where the judge was allegedly recovering from his wound. The murderer made her attack, and ZX-5 grabbed her by the arm. Breaking free, she rushed up to the roof with ZX-5 right behind her. When she tried to attack him with a shovel, she slipped off the roof and fell to her death many stories below. When unmasked, the dead woman proved to be the prison matron, who had lost to the judge in an election years ago and hated him with a passion. She had killed the guard when he had seen her tear a piece out of Violet's dress in the morgue.
Roulf: 1940, Fanastic Comics 12 (Fox). Editor of the Daily Standard. Also a masked leader of a group of Nazi spies and saboteurs. Defeated by Samson and David.
Vance Roy: Amazing Mystery Funnies (Centaur). In the Year "X" (circa 2500 AD), he bedevils King Kurt and the heroes Skyrocket Steel, Invex, and Sari Marston.
Rubberman: 1943, Air Fighters #6 (Hillman). Herr Riktor is head of a rubber factory in Nazi Germany. When British bombers destroy his plant, he falls into a vat of hot liquid rubber which burns away his skin and somehow, through hate and force of will, he doesn't die but the rubber bonds to his body, allowing him to stretch and bounce and even deflect bullets. While fighting the Iron Ace, he is hit so hard he ricochets off the walls and into a boiling hot vat that seems to dissolve and kill him. NOTE: One of the more interesting and unique supervillains I've come across.
Ruby Khan: 1945, Heroic Comics #29 (Eastern Color Pringing). Ruby Khan is a stage magician who uses his shows as ways to steal valuable jewelry, substituting convincing fakes in their place. His crimes are uncovered when one hierloom that is stolen was on the way to get appraised the next day and the theft is thus deiscovered. Despite his magic tricks, he's captured by Hydroman.
Ruk: ?1946, Super-Mystery Comics v6 #2 (Ace)?. Murderous and cunning criminal. In this appearance, he escaped from prison, suggesting that he'd appeared before. Caught by Magno and Davy.
The Ruler of the Underseas: 1940, Weird Comics #1 (Fox). An evil underwater villain, he rules from his underwater castle various giant sea serpents, serpent-men and even enchants a beautiful surface woman to do his bidding alongside his monsters. He was stopped by Typhon. NOTE: For reasons that aren't clear, the woman would show up with the undersea blonde amazons in issue #5 and Typhon aims to escort her to the surface where she belongs. Makes me wonder if one of the villains of issue 5, Mikal, the leader of the undersea pirates and self professed ruler of the deep is supposed to be the Ruler of the Underseas in issue 1.