TV's "The Incredible Hulk" would have featured a red Hulk, not the green-skinned Hulk so familiar to comic-book fans, if the show's creator had had his way. Early plans for Marvel's "Wolverine" envisioned the hero as a mutated wolverine that thinks it's a man.

And Batman's most famous foe, the Joker, would have been a short-lived one, killed off in 1940's "Batman" No. 1, if not for a last-minute editorial change.

These are just a few of the many gems contained in "Was Superman a Spy?" a new book from Plume that "demystifies all the interesting stories, unbelievable anecdotes, wacky rumors and persistent myths" from comic-book history.

The book was spun out of writer Brian Cronin's online column, Comic Book Legends Revealed, which he started about four years ago. The column, in turn, was sparked by an item he wrote for his blog about writer/artist Walt Simonson's stint on "Fantastic Four." Problem was, the item -- which mentioned a list Simonson had supposedly kept of past appearances by the villainous Doctor Doom that he thought should be ignored -- was wrong; there was no such list.

"Walt e-mailed me and said, 'Actually, that's not what happened,'" Cronin recalled. And that got him thinking about "all these various little stories and rumors" that he'd heard over the years as a comic-book fan. So he began investigating comic book "urban legends."

Over the years, Cronin has researched everything from how the original Green Lantern was shoved off the cover of his comic book to make room for a dog to "Star Trek: The Next Generation" star Jonathan Frakes' early appearances as Captain America at comic-book conventions. ("Frakes took the role seriously and was an excellent Captain America, putting up with the fans and their questions with grace and aplomb," Cronin writes.)

"It's amazing when I look back," he said. "When I first started, I just had this little tiny notebook where I would just write ideas, and when I ended up confirming yes or no, I would cross them out. After a while, that just became quite silly, so I put it all onto the computer."

Cronin's column passed its 200th installment not long ago. The items that get the most fan response, he said, typically involve comics' big guns -- characters such as Spider-Man, Batman and the X-Men.

"But some of the most fascinating ones," he said, "are about the more obscure characters." He mentioned a recent column he did on Skippy peanut butter and how it co-opted the name Skippy from a popular comic strip.

"Nobody thinks of the comic strip character anymore," he said.

Cronin recently started delving into legends from sports and entertainment at www.legendsrevealed.com. His Comic Book Legends Revealed appears at www.comic bookresources.com.