Easter egg: There is a hidden sketch on S6 disc 4. Go to the Special Features menu, highlight "Play all deleted scenes with commentary", then press right. A pencil icon will appear. Press enter to see a sketch of the Simpson home made up of squirrels.
Easter egg: Season 6 DVD. Select the last disc, and go to The Who Shot Mr Burns part 1 episode menu. Click up to select the members on the picture and click enter for gunshots.
Easter egg: Disc one: go to the menu for Treehouse of Horror V. Click up to select the numbers in the picture, then press enter to see an eye.
Easter egg: On Disc 1 of the Complete Sixth Season, there is the option to access a hidden sketch. If you watch "Treehouse of Horror V" with either the commentary or the option for deleted scenes on, when the shot of the Simpson house transforming into different forms is shown, a picture of a pencil appears in the lower right corner. Press 'Enter' to see a sketch of the Simpson house made entirely out of squirrels.
Answer: Willy referred to an encounter he believed he had with actual aliens, while Wiggum thought he was referring to the arcade game.