The Fighting Devil Dogs (1938) is a 12-chapter Republic movie serial starring Lee Powell and Herman Brix, the latter better known by his later stage name, Bruce Bennett. It was directed by William Witney and John English. While not often considered one of the best serials ever made, as it contains a lot of stock footage and two recap chapters, it is famous for its main villain, The Lightning—the very first costumed supervillain. There is some speculation that George Lucas used The Lightning as a template for Darth Vader.

Plot
In Singapore, two Marine Lieutenants, Tom Grayson and Frank Corby, uncover the threat of a masked terrorist called The Lightning, who uses an arsenal of powerful lightning-based weaponry in his bid for world conquest. However, the battle becomes personal when The Lightning annihilates the officers’ unit and later kills Lt. Grayson’s father as he was helping the investigation of the weapon. Now, the marines have dedicated themselves to stopping The Lightning and bringing him to justice.

Cast
Lee Powell as Lt Tom Grayson
Herman Brix as Lt Frank Corby
Eleanor Stewart as Janet Warfield
Montagu Love as General White
Hugh Sothern as Ben Warfield/the Lightning
Sam Flint as Col Grayson
Perry Ivins as Crenshaw
Forrest Taylor as Benson
John Picorri as Prof Gould