Although he wasn't given proper credit during his lifetime, Bill Finger is now known as the true creator of Batman. Batman's other creator, Bob Kane, took all of the credit for Batman's creation. In actuality, Bob Kane mostly just came up with the initial idea for Batman. Most of what made people fall in love with Batman came from Bill Finger's creative mind. For decades, Bob Kane got 100% credit for Batman's creation, as well as a majority of the money and fame. However, Bill Finger got to retain his morality and humbleness. Because of this, I believe he was the true heart and soul of Batman.

Bill Finger helped co-create the following heroes from the Batman series:

Batman

Commissioner Gordon

Robin (the Dick Grayson version)

Batgirl (the Betty Kane version)

Ace the Bat-Hound

Bat-Mite

Bill Finger helped co-create the following Batman villains:

Hugo Strange

Joker

Catwoman

Penguin

Two-Face

Riddler

Clayface

Scarecrow

Mad Hatter

Sal Maroni

Catman

Killer Moth

Kite Man

Calendar Man

Polka-Dot Man

Other important characters that Bill Finger co-created:

Green Lantern (the Alan Scott version)

Thomas and Martha Wayne (Bruce Wayne's parents)

Harriet Cooper (Dick Grayson's aunt)

Wildcat

Lana Lang

Legacy:

Bill Finger's characters have continued to remain iconic legends. His most popular creation, Batman, has become one of the most popular fictional heroes of all time. Robin has grown into an incredibly popular sidekick and has become the leader of the Teen Titans. The Joker is often considered to be one of the greatest adversaries of all time. Penguin, Catwoman, Two-Face and Riddler are also considered to be amongst the greatest supervillains of all time. Even some of Bill Finger's most obscure villains, like Kite Man and Polka-Dot Man, have gotten a fanbase in recent years.

Bill Finger is the most influential and important person in Batman's entire legacy. His wonderful contributions have left a wonderful impact on the world. His legacy has and will continue to make the world a brighter place.