In Deadmines, a Death Knight is able to raise an ally as a ghoul if someone dies before him/her. Cookie will never target the ghoul to throw food at, and the ghoul will never get hit by the AoE on the ground. If the player that is a ghoul keeps attacking Cookie it will keep him in combat so he will not despawn, allowing other players in the group to run back if you happen to wipe.
Not game breaking, and Cookie isn't an extremely hard boss but this might be applicable in other situations as well.
Cheers,
~Kor