Sh! The Octopus (1937)

Starring Hugh Herbert, Allen Jenkins, Marcia Ralston, John Eldredge, George Rosener
Directed by William McGann
(actor & director credits courtesy IMDB.com)

A pair of bumbling detectives try to solve a mysterious murder at a lighthouse, which may be the work of "The Octopus," a criminal boss with real tentacles.  

Warner Brothers presents a very silly mystery-comedy, with several actors practicing their comedy shtick, most notably Herbert with an avalanche of puns and Jenkins playing his usual dimwitted persona.  Just when you think you can start to take the mystery plot seriously, some silly sight gag is unleashed on the audience, as when the long tentacles of an octopus grab one of the characters or Herbert disassembles a ladder trying to climb down it.  It's not a great comedy, but it is entertaining, and the team of Herbert and Jenkins are amusing enough.

The Black Cat (1941)

Starring Basil Rathbone, Hugh Herbert, Broderick Crawford, Bela Lugosi, Anne Gwynne
Directed by Albert S. Rogell
(actor & director credits courtesy IMDB.com)

A real estate agent trying to buy the mansion of a wealthy spinster discovers one of her heirs may be ready to murder to obtain their inheritance.

A long-time favorite film of mine, this comic mystery from Universal Pictures features a great cast, atmospheric photography, some funny lines, and wonderful music culled from the scores of the studio's horror classics.  Crawford is extremely likable as the bumbling hero in one of his earlier roles, Hugh Herbert gives us some memorable schtick, and old pros like Rathbone, Lugosi, and Gale Sondergaard play the proper notes as sinister murder suspects.  On top of all that, the script offers a well-constructed whodunit plot, leaving the murderer's identity unclear until the final climax, but dropping enough clues before then to make for a logical conclusion.