How does Fair Use apply to parody?

Parody is an artistic work that imitates the characteristic style of another work for comedic effect or ridicule.

Because a successful parody needs to mimic the original, you can generally borrow more than with other types of uses. One important caveat: You can borrow only as much as you need to fully express the parody or clue in the audience to the joke. Parodies that borrow too liberally from the original may be legally problematic. 

Whether a work is considered a valid parody under fair use also depends on the extent to which the new work adds elements that comment upon or criticize the original work. Works that use other works for the purposes of getting noticed don’t qualify. In the Supreme Court’s words, “uses to get attention or to avoid the drudgery in working up something fresh” will have a more difficult claim to fair use.