Lady and the Tramp (1955)

Continuity mistake: When Lady is running away from the pet shop she is chased by the angry mutts. The middle dog's inner ear color is solid green yet in the next scene is pink. (2006 edition).

Lady: ...But when she put that horrible muzzle on me.
Tramp: Say no more, I get the whole picture. Aunts, cats, muzzles... Well, that what comes of tying yourself down to one family.
Lady: Haven't you a family?
Tramp: One for every day of the week. The point is, none of them have me.

Trivia: Although the spaghetti-eating sequence is now the best known scene, Walt Disney originally did not want it in the film as he thought it would not be romantic and that two dogs eating spaghetti would look ridiculous. Animator Frank Thomas was against Walt's decision and animated the entire scene himself without any lay-outs. Walt was so impressed with Thomas's work he decided to keep the scene in.