The individuals who plotted to kill Daniel were:
* Darius the Mede: The king of Babylon at the time. He was tricked by his advisors into signing a decree that would make it illegal to pray to any god but Darius for 30 days.
* The King's advisors: These were the people who persuaded Darius to sign the decree. They were likely motivated by jealousy and resentment of Daniel's position of power and influence.
It's important to remember that the book of Daniel is a religious text, and the story of Daniel's survival is meant to illustrate his faith and God's protection. The plot to kill him is symbolic of the challenges and dangers that believers may face in their lives.