The Shielding Shadow

The Shielding Shadow
Overview
The 15 chapter story involves the heroine being protected by a shadow with burning eyes. There's also a cloak of invisibility, some hypnotism and a giant octopus added to the mix.
Similar
The King of the Kongo (1929)
The Phantom Rider (1946)
Flash Gordon (1936)
Drums of Fu Manchu (1940)
The Wolf Dog (1933)
Perils of the Royal Mounted (1942)
Troopers Three (1930)
King of the Forest Rangers (1946)
The Phantom Rider (1936)
Bruce Gentry (1949)
The Secret of the Submarine (1915)
Jesse James Rides Again (1947)
The Scarlet Horseman (1946)
The Master Key (1945)
Mystery of the Riverboat (1944)
Sea Raiders (1941)
Spy Smasher (1942)
Jungle Queen (1945)
The Adventures of Dusty Bates (1947)
The Great Adventures of Captain Kidd (1953)