First appearance

Clayface
Basil Karlo
Flash
Hawkman
Lwaxana Troi
The Crimson Avenger
Superman
Zatara
Lex Luthor
Joker
Catwoman
Ultra-Humanite
Batman
Jason Todd
Hugo Strange
Dick Grayson
Robin

Clayface

Sources

Title	Type	Date	Platform	Names	Characters	Series
The Murders of Clayface	Comic	1940-06		Bill Finger, Bob Kane, Jerry Robinson	Batman, Clayface

Basil Karlo

Sources

Title	Type	Date	Platform	Names	Characters	Series
The Murders of Clayface	Comic	1940-06		Bill Finger, Bob Kane, Jerry Robinson	Batman, Clayface

Flash

Sources

Title	Type	Date	Platform	Names	Characters	Series
Flash Comics #1	Comic	1940-01				Flash Comics

Hawkman

Sources

Title	Type	Date	Platform	Names	Characters	Series
Flash Comics #1	Comic	1940-01				Flash Comics

Lwaxana Troi

Sources

Title	Type	Date	Platform	Names	Characters	Series
Haven	Episode	1987-11-30		Lan O'Kun, Richard Compton, Tracy Tormé	Deanna Troi, Lwaxana Troi	Star Trek: The Next Generation

The Crimson Avenger

Sources

Title	Type	Date	Platform	Names	Characters	Series
Detective Comics #20	Comic	1938-10				Detective Comics

Superman

Sources

Title	Type	Date	Platform	Names	Characters	Series
Action Comics #1	Comic	1938-04-18				Action Comics
Revolution in San Monte, part one	Comic	1938-04-18		Jerry Siegel, Joe Shuster	Lois Lane, Superman

Zatara

Sources

Title	Type	Date	Platform	Names	Characters	Series
Action Comics #1	Comic	1938-04-18				Action Comics

Lex Luthor

Sources

Title	Type	Date	Platform	Names	Characters	Series
Action Comics #23	Comic	1940-02-22				Action Comics

Joker

Sources

Title	Type	Date	Platform	Names	Characters	Series
Batman #1	Comic	1940-06		Bill Finger, Bob Kane	Batman, Catwoman, Hugo Strange, The Joker	Batman

Catwoman

Sources

Title	Type	Date	Platform	Names	Characters	Series
Batman #1	Comic	1940-06		Bill Finger, Bob Kane	Batman, Catwoman, Hugo Strange, The Joker	Batman

Ultra-Humanite

Sources

Title	Type	Date	Platform	Names	Characters	Series
Action Comics #13	Comic	1939-05-02		Jerry Siegel, Joe Shuster	Ultra-Humanite	Action Comics

Batman

Sources

Title	Type	Date	Platform	Names	Characters	Series
The Case of the Chemical Syndicate	Comic	1939-05		Bill Finger, Bob Kane	Batman, James Gordon

Jason Todd

Sources

Title	Type	Date	Platform	Names	Characters	Series
Did Robin Die Tonight?	Comic	1987-06		Adrienne Roy, Chris Warner, Max Allan Collins, Mike Decarlo	Batman, Jason Todd, Ma Gunn	Batman

Hugo Strange

Sources

Title	Type	Date	Platform	Names	Characters	Series
Detective Comics #36	Comic	1940-02			Batman, Hugo Strange	Detective Comics

Dick Grayson

Sources

Title	Type	Date	Platform	Names	Characters	Series
Detective Comics #38	Comic	1940-04				Detective Comics

Robin

Sources

Title	Type	Date	Platform	Names	Characters	Series
Detective Comics #38	Comic	1940-04				Detective Comics