on the first disk's episode guide, go to the second page and to the left of the screen is a light switch, once you get it highlighted click on it and it will show a fan concert (theme song song by group of kids 'round there 20's
On the second episode screen, there is a small spot of something on the floor, and this is the "left right puppet song".
On Disc One go to the episode guide and highlight the Christmas Tree lights for werewolf puppets.
On Disc One go to the episode guide and highlight the chip on the floor for vegetable man.
On Disc One go to the episode guide and highlight the Stove Knob for puppet bowling.
All easter eggs were generously submitted by SirDonk