When suit-wearing henchmen don aprons and prepare vegetables in the kitchen (Oscar, 1991), or a hunchback's hump switches to the opposite shoulder (Young Frankenstein, 1974), it creates comedy through incongruity--something that doesn't match up with what we expect.
Using an object in an incongruous (unexpected) way is funny. For example, when Jeff Blue (Dennis Quaid) uses a baby stroller to defeat a mugger (Undercover Blues, 1993).
Later, when the mugger, Muerte "My name is Death!" (Stanley Tucci), screams like a girl, it cracks me up. His behavior doesn't match the stereotype of a thug.
When Connie Conehead (Michelle Burke) consumes an entire foot-long sandwich in one bite, that can be expected from an alien. However, when her boyfriend, Ronnie (Chris Farley) exclaims, "Wow! My Mom's the only other woman I know who can take a sandwich like that!" I crack up. That is not what I expect him to say! (Coneheads, 1993)
Alex Hitchens' (Will Smith) love life seems incongruent (Hitch, 2005). He coaches men on winning the girl of their dreams, yet fails in his own dating strategies. Shouldn't the maestro of matchmaking have all the right moves? His dates with Sara (Eva Mendes) turn disastrous, creating great comedy for the film!
Here's a clip of their first date (and it only goes downhill from there):
Do you have a favorite incongruous moment in a movie?