Although it is not an official element of the holiday or its
celebration, the phenomenon of the Festivus Miracle is
mentioned twice in the original episode. An obvious sendup to
the phrase "Christmas Miracle", both manifestations of
Seinfeld's "Festivus Miracle" were caused by Kramer. In
today's society the use of the term "Festivus Miracle" has
become far more mainstream.
Ex of a Festivus Miracle: