In his analysis of fairy tales, Vladimir Propp identified this role as the "donor" and listed it as one of the seven roles found in fairy tales. Before giving the hero magical support or advice, the donor may also test the hero, by questioning him, setting him tasks, or making requests of him. Then, the donor may directly give the hero a magical agent, advise him on how to find one, or offer to act on his behalf. If the character itself acts on behalf of the hero, it also takes on the role of "helper" in Propp's analysis. Because a donor is defined by acts, other characters may fill the role, even the villain; a boy escaping a witch may steal her magical handkerchief, making the witch an involuntary donor. Conversely, the donor of "Rumpelstiltskin" converts himself into the villain by demanding the heroine's baby as the price of his work.