A character from Osamu Tezuka's Unico manga debuting in "The Tale of the Fangs of Athens" chapter. Sphinx is a female mother sphinx with blue colored hair and fur and the mother of Piro (known as Marusu in "Unico in the Island of Magic").

In the manga, Unico first encounters Sphinx in the middle of a desert who asks him to solve her riddles or ends up becoming food to her son Piro. After Unico passes out due to lack of food and not good at solving riddles, she takes him to a cave that she and her son live in. Piro gets tired of having meat and whines that he wants something else to eat. After Sphinx's son spares Unico's life by singing him "Pink Lady" songs, he becomes friends with the unicorn. When Unico finds Sphinx again, she's dying after Oedipus killed her after solving her riddle. Unico promises Sphinx to make sure Piro becomes a "Strong and Sturdy Sphinx" after her death. After discovering her death, Piro vows to make a giant sand sculpture of Sphinx in memory of his mother.

In the 2000 short "Saving our Fragile Earth: Unico Special Chapter", she's depicted with brown fur and blonde colored hair. In the short, she helps Unico, Tsubada, and The Spirit of Time travel back in time to prevent the earth from becoming completely deserted and polluted. Unlike the manga, Sphinx isn't a mother with no mentions of Piro.

In the English-language manga reboot series, Sphinx becomes depressed after witnessing Venus kidnapping her daughter Marusu. She initially tries attacking and almost eating West Wind due to her association with Venus. After West Wind explains that she's trying to end Unico's cylcle getting his memories erased to her. Sphinx decides to help the wind spirit by giving her cryptic hints to help Unico regain his memories.