The tale of the magician and his sheep
There once was a magician who had a flock of sheep that he was farming for their skins and flesh. The sheep did not like that, and sometimes some of them would get away, while others wandered off and fell into ravines, and some of them were taken by wolves. The magician was too stingy to get himself a shepherd to look after the sheep, and so he pondered his problem until he came up with the perfect plan.
He put the sheep in a hypnotic state and told them first of all that he is a good master who loves them very much and wants only the best for them.
He then tells them that if there is any danger it is of no concern to them at the present time. He told them that they are immortal, and that their killing and skinning was not at all scary but rather a pleasant experience for them. Lastly he told some of them that they were wolves, some of them that they were eagles, and some of them he told that were magicians themselves.
And so he was able to farm them for their skins and flesh without ever having to worry about them running away again.