Leif Erikson Day is a minor holiday celebrated in the episode "Bubble Buddy." Patrick wishes SpongeBob a Happy Leif Erikson Day and at the end of the episode, Bubble Buddy wishes him a Happy Leif Erikson Day before drifting off into a Bubble Taxi.
On Leif Erikson Day, "hinga-dinga-durgin" is said and a viking helmet and red beard are worn.
- Leif Erikson Day is an actual US national holiday, celebrated annually on October 9, that commemorates both the Icelandic-Norwegian explorer Leif Erikson first setting foot in North America, and the accomplishments and contributions of Nordic-Americans in American history and society. It was originally proposed as an alternative to the federal holiday, Columbus Day, by those that thought Erikson should have been celebrated instead of Columbus, due to the explorer discovering North America 500 years before Columbus did.
- National Geographic gave a brief mention of SpongeBob celebrating the holiday in this article, along with also mentioning his love for April Fool's Day.