Who's This? By popular demand! This Golden Age hero only got half of page 15 in Who's Who vol. XIX, but people care!
How you could have heard of him: As a long-running joke or someone's personal obscure favorite, perhaps. And that's true of comics writers too. Grant Morrison is in the former camp, making him as a denizen of Limbo in Animal Man, and an old buddy of Plastic Man in JLA. James Robinson uses him more seriously in Golden Age and as a ghost in Starman. Still, nothing major. More recent Freedom Fighters comics gave the name to an insectoid female hero/villain.
Example story: Hit Comics #13 (1941) by Toni Blum and Witmer Williams (all or most of his strips were, regardless, signed by the pseudonym B.H. Apiary)
Hercules, X-5 Super Agent, Jack and Jill, The Strange Twins, The Old Witch, Bob and Swab, Blaze Barton, the Great Defender/Stormy Foster, Betty Bates, Comet Kelly, the Ghost of Flanders, Captain Flagg, Don Glory, Lion Boy... Until Kid Eternity took over the book with #25, it seemed "Hit Comics" was unable to produce a character with as much staying power as the Red Bee! Only Neon the Unknown has arguably done as well (as the name used by a character in the modern Freedom Fighters), but I wouldn't take Neon's side if there's an argument about that. Really says something about the first two years of this book, doesn't it?
Who else? Moving over to Golden Age Fawcett Comics, I'm skipping to Who's Who vol.XX to do so.
*Milk racketeering IS a real crime, I know, but it still sounds incredibly silly. Google's first hit links to a 1933 case.