Religion: manifestly non-religious
Name: unnamed gambler gangster
First Appearance: Superman (vol. 1) #2 (Fall 1939): "The Comeback of Larry Trent"
Number of appearances: 1
Allies: Tom Croy
Heavyweight boxing champion Larry Trent's crooked manager Tom Croy "worked hand-in-glove with ruthless gangsters." Croy made a deal with one particular gambler ganster (nameless, but depicted in multiple panels on various pages in this story) who made a deal with Croy to have Trent throw the championship bout. Larry Trent was too honorable to throw a fight, but Croy made his own arrangements. He drugged Trent the night before the fight, causing Trent to lose the fight. Trent's career went into a tailspin until Superman helped him stage a comeback. Right before Trent was to fight in a new championship bout, Tom Croy re-introduced himself, unaware that Trent knew about the earlier drugging. Croy tried to pull the same trick he had done before, working with the same gambler gangster to bet against Trent and then cause Trent to throw the fight by drugging him.
The gambler ganster wanted assurances. He stood by ready with a gun in case drugging Trent didn't work. In fact, Tom Croy failed to drug Trent, because Trent refused to drink what Croy offered him and then Superman grabbed Croy away from the ring. As the narration describes, "Wrathful at seeing his crooked scheme foiled, Croy's gambler-accomplice prepares to fulfill his threat to kill Larry!"
The gambler gangster pulled out his handgun and tried to murder boxer Larry Trent. But Superman covered the gun with his hand, causing the weapon to explode in the killer's face.
The gangster gambler is specifically identifid as a "killer" in the narration, suggesting that he may have murdered before. But whether or not he is actually a murderer or merely an attempted murderer due to this story's attempt, this unnamed gambler gangster, the accomplice of crooked boxing manager Tom Croy, can clearly be classified as manifestly non-religious.
This character is in the following story which has been indexed by this website:
Superman (vol. 1) #2 (Fall 1939): "The Comeback of Larry Trent" (4-panel cameo)