Angel of Death
During the series pilot, an angel of death named Adam is introduced. In the season two premiere, "Interview with an Angel", a new Angel of Death named Henry is introduced. Then in the season two episode entitled "The One That Got Away", Andrew (played by John Dye) is introduced as the Angel of Death. Initially a recurring character, he becomes a main character in season three, making him the permanent Angel of Death for the remainder of the series. The original angel of death, Adam, continued to appear in guest appearances over the next few seasons.