Spaceballs (1987)

Continuity mistake: The head of Mega-Maid mysteriously shrinks in size. After Spaceball-1 transforms into Mega-Maid, the head is gigantic enough for a Winnebago to fly through for a considerable length of time. However, later on in the film, after the head has been jettisoned and crashed on a beach, the head is only big enough to hold a few dozen people. This can be determined by the size of the people coming out of her nose.

Computer: This ship will self-destruct in exactly ten seconds. Counting down. Ten, nine, eight, six.
President Skroob: Six? What happened to seven?
Computer: Just kidding.

Trivia: When Skroob's ship arrives at Planet Druidia, Colonel Sandurz says the ship is preparing for metamorphosis to which Lord Helmet says "Ready, Kafka?" Franz Kafka wrote the book "The Metamorphosis."