xkcd #3202: Groundhog Day Meaning
Title text:
Originally, the ceremony used a variety of rodents and mustelids, but over time most people agreed it made sense to standardize on a specific individual ground squirrel in Pennsylvania.
Transcript:
Transcript will show once it’s been added to explainxkcd.com
Source: https://xkcd.com/3202/
the eggs thing predates christianity, so these things weren't all invented at once. people just kept on adding more and more outrageous shit