What's the Kennection? #397

What Planters advertising mascot was killed off in a fiery car crash in the run-up to Super Bowl LIV?

In "The Adventure of the Red-Headed League," what literary smoker referred to a tricky mystery as a 'three-pipe problem"?

What director, labeled by Nazi Germany as a "disgusting Jew acrobat," lampooned Hitler himself in 'The Great Dictator'?

To amuse his children in letters home from World War I, Hugh Lofting created what physician who talks to Polynesia the parrot and the pushmi-pullyu?

What Black Sabbath song is about a powerful time traveler who "was turned to steel in the great magnetic field"?

What's the "Kennection"?