Season 9, Episode 10: "The Strike"

Kramer, I got your message.

I haven't celebrated Festivus in years.

-What is your interest? -Well, just tell me everything.

Many Christmases ago, I went to buy a doll for my son.

I reached for the last one they had, but so did another man.

As I rained blows upon him, I realized there had to be another way.

-What happened to the doll? -It was destroyed.

But out of that a new holiday was born.