"The Magic Egg" is based on a 1960 comic story titled, "L'Oeuf et les Schtroumpfs" ("The Egg and the Smurfs" in English). It originally appeared as a detachable supplement in Spirou (a prominent Belgian comic magazine formerly called "Journal de Spirou"), but was serialized with modern character designs in 1966. Unlike the cartoon adaptation, the original comic story has noticeable differences:
- The magic egg was not created by Gargamel and it was not stolen and lost by Bigmouth the ogre (who did not appear in the comic story). Its origins are unexplained.
- Gargamel does not appear in the original comic story.
- Smurfette does not appear in the original comic story as it pre-dates her 1966 debut in "La Schtroumpfette" ("The Smurfette" in English).
- Papa Smurf wished himself as a young Smurf instead of a monkey as depicted in the cartoon version.
- The egg is not large and golden-colored, but normal-sized and white-colored.
- The egg did not disappear by Papa Smurf, but it hatched revealing a young chick that grows up to be a rooster to the shock of an unnamed Smurf who built an enclosure in the thought it will grow up to be a hen and lay magic eggs.
"Smurphony in C" is based on the 1963 comic story "Schtroumpfonie et Ut." It is the first Smurf comic story to be serialized as previous ones appeared as detached supplements in Spirou.
In "The Magic Egg", while in monkey form, Papa Smurf speaks with an echoing tone.
In "The Magic Egg", the deeper tone Clumsy speaks in when he is grown is the voice William Callaway used as his regular voice, though pitch-shifted in production.
In "Smurphony in C", Gargamel squashed Azrael flat with his door while calling for him. This never happened in the original comic story.