I'm not sure if this is a trpe, but I belive this is the website it belongs on.
This is for works that have the exact opposite plots to each other.
Example 1: A Christmas Carol
, A Wonderful Life
In one, 4 ghosts tell you to mend you ways, or no-one will morn for you when you die. In the other, an angel tells you not to comit suicide because everyone loves you.
Made more fitting because these are the two most common plots for Christmas specials.
Example 2: My Fair Lady
, Rocky Horror Show
In one, a woman is taken off the street and taught to act like a lady. In the other, two prim and proper young people are taught to be depraved sex-mad hedonists.
Made more fitting because they're both musicals.
Example 3: Scoobydoo , The X-Files
In one, a hippy never looses his belief in the supernatual, despite them constantly proved to be tricks. In the other, an FBI agent refuses to beleve in the supernatual, despite constantly seeing it.