Batman: Detective No. 27

Batman: Detective No. 27 is a one-shot 2003 Elseworld comic where Bruce Wayne never becomes the Batman, but is instead GCPD Detective No. 27. It is worth noting that the character of Batman first appeared in Detective Comics #27.

Tropes used in Batman: Detective No. 27 include:

Absolute Cleavage: Catwoman.
Animal Motifs: Unsurprisingly, bats are all over the place.
Freud Was Right: Actually invoked by name a couple times. Freud himself makes an appearance, and yes he does have a cigar.
Historical Domain Character: Quite a few.
- Abraham Lincoln.
- Allan Pinkerton.
- John Wilkes Booth.
- Charles Darwin (Sort of. It's actually Pinkerton).
- Kate Warne.
- Theodore "Teddy" Roosevelt.
- Gregor Mendell.
- Babe Ruth.
- Sigmund Freud.
- Franklin Delano Roosevelt.
- Fiorello La Guardia.
Jekyll and Hyde: The Trope Namer makes a cameo.
Massive Multiplayer Crossover: Aside from the usual Batman crew, we have Superman, The Crimson Avenger, Mr. Hyde, and a detective in the Secret Society of Detectives that looks an awful lot like Hercule Poirot.
Mythology Gag: Lots and lots. Babe Ruth calling Bruce "the Bat-Man" being the most obvious.
- Batman first appeared in Detective Comics #27.
- Joe Miller's Joke Book.
- Bruce mentions how he called Robert Frost "Mr. Freeze" when he was a boy.
- Catwoman dressing up as an old lady and Bruce recognizing her legs.
- When Bruce is under the influence of Datura spores, he hallucinates Jonathan Crane becoming the Scarecrow.
- "As if in answer, a huge bat flies through the open window..."
- Jack Napier from the Tim Burton films shows up.
- "Do you envision yourself as some noble, dark knight, detective?"
Wham! Line: "Didn't anyone ever teach you not to be so certain about life? And here I always assumed you'd be as bright as me...Son!"
World of Badass: Pretty much.