A figure cut or engraved on metal or stone, under the influence of certain planets. In order to free any place of vermin, the figure of the obnoxious animal is made in wax or consecrated metal, in a planetary hour, and this is called the talisman. (Warburton.)
He swore that you had robbed his house, And stole his talismanic louse.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894
More on Talisman from Infoplease: