Goofs:
Continuity: After the magician drops the eggs on the floor in the classroom, there is one half of an eggshell on the ground to the right. When he covers the mess, the eggshell all of a sudden turns into a dice piece and flies off screen and disappears. (more)

Trivia:
Voice actress June Foray was cast for both Karen and the Teacher and had recorded vocals for both characters. However, only her recordings for the Teacher made it into the final special as another actress was called in to replace Foray's Karen, for reasons that even Foray herself to this day does not know. No changes were made to the credits, so the actual voice actress we hear as Karen remains unknown and uncredited. Foray's Karen can be heard on the Rhino Records soundtrack. (more)

Quotes:
[repeated line]
Frosty: Happy birthday!
(more)