Grouches of yesteryear celebrate Crankymas.

Crankymas is the Grouch alternative to Christmas, as introduced in the 2016 special Once Upon a Sesame Street Christmas. It is not explicitly stated whether or not the holiday occurs on December 24 or 25th, as Grouches are shown celebrating on Christmas Eve.

According to Oscar the Grouch, the holiday is celebrated by inviting one's Grouch family over to argue and give each other gifts of junk. Sludge is a popular beverage associated with the holiday.