Angel of Death also known as 'AOD', will make a flying dragon appear out of nowhere that will eat enemy followers and the shaman. If the dragon tries to eat somebody inside a building, the building will be destroyed as the follower is being snatched. Usually is stopped by using Ghost Army.
The Angel of Death has a great amount of health points, but can be defeated with damaging spells/firewarrior shots - for instance, firestorm will damage it; an enemy Angel of Death will battle it, and usually, whoever has greater health will destroy the other (else, both will perish). It can also be destroyed by 4 direct lightning stikes or if a large number of firewarriors attack it at once. If it doesn't get destroyed, it usually goes away in 3 - 5 minutes. It is possible for a good part of the tribe to be decimated with a good Angel of Death.