The 10th Plague of Egypt
Death of Firstborn
Pharaoh's Son Died Lesson
(with lots of stuff to go with it)
Exodus 11:5-And all the firstborn in the land of Egypt shall die, from the firstborn of Pharaoh
that sitteth upon his throne, even unto the firstborn of the maidservant that is behind the mill; and all the firstborn of beasts.