The Sphinx required a very specific and orderly response to its riddle. Once the formality was out of the way, though, it talked about its desire to find a female Sphinx as well as its love of good food — mostly farm animals.
The heroes met the Sphinx again standing guard over the Pyramid of Shadows. It told them that it had been offered a better deal by the army that invaded the Desert Fortress, and that it was required to issue two riddles. The heroes answered the riddles and entered the Pyramid.