Lame Xander: Every Christmas, we watch Charlie Brown together, and I do the Snoopy Dance.
A Charlie Brown Christmas was the very first animated prime-time special to feature Charlie Brown, Snoopy, and the rest of the characters from Charles Schultz's comic strip Peanuts. First broadcast on December 9, 1965, it has become a perennial favorite, shown every year on television around Christmas time. It also featured the debut of "The Snoopy Dance."
Willow and Xander's annual tradition was first mentioned in season 2's "Passion" and in several episodes thereafter.