Riddle of the Sphinx

Nobody knows.

https://www.loc.gov/item/2001704570/

https://www.loc.gov/item/2004666752/

https://www.loc.gov/item/2017656954/

https://www.loc.gov/item/mpc2004005110/PP/

https://www.loc.gov/item/2004707274/

https://www.loc.gov/item/90713671/

https://www.loc.gov/item/90713677/

https://www.loc.gov/item/2004707593/

https://www.loc.gov/item/mpc2004002782/PP/

https://www.loc.gov/item/mpc2010003452/PP/

https://en.wikipedia.org/wiki/Great_Sphinx_of_Giza