تعریف و معنای "pull the other (one|leg) (, it has got bells on|)"

What is the origin of the idiom "pull the other one" and when to use it?

The idiom "pull the other one" is a humorous and somewhat sarcastic expression used to express doubt or skepticism regarding something someone has said. The origin of this phrase is not precisely documented, but it is recognized as a playful and somewhat tongue-in-cheek way of challenging the credibility of a statement.