Festivus

(CNN) — It’s December 23, so “let’s rumble!”

As last-minute shoppers fueled on eggnog scramble for those final gifts for relatives thrice-removed, there’s another celebration afoot Tuesday: Festivus.

Festivus was introduced in the ninth and final season of “Seinfeld” as a holiday that George Costanza, played by Jason Alexander, begrudgingly grew up with as an antidote to the season’s growing focus on consumerism.

While the episode originally aired on December 18, 1997, the holiday and its eccentric customs — like the “feats of strength” and “airing of grievances” — live on with much fanfare.