The originalheld the mantle from 1941
Dr. Jonathan Crane
Powers. No superpowers; genius psychologist and biochemist who weaponizes a hallucinogenic fear toxin that induces victims' deepest fears. Master strategist/manipulator, skilled hand-to-hand combatant. Occasionally transforms into the monstrous "Scarebeast."
Origin
Professor Jonathan Crane was a psychologist with an obsessive fascination with fear who turned to crime, adopting the unsettling guise of the Scarecrow to terrorize Gotham City and becoming one of Batman's earliest recurring foes. Armed with a fear-inducing gas and a ghoulish straw-man costume, he weaponized the science of phobia itself against his victims.