Before changing the narration, optative sentences are first converted to assertive sentences.
The Governor of the town asked the slave, "How has this hungry lion forgotten his nature?" The slave replied, "This very lion which is standing before you was my friend in the woods."

Explanation

The governor of the town asked the slave how the hungry lion had forgotten his nature. To this the slave replied that very lion which was standing before him had been his friend in the woods.