The alchemist Paracelsus (1493-1541) was thought to have kept an imp trapped in the crystal pommel of his sword. Artwork shows that the pommel was labeled with the word Zoyh, which was thought to be the name of the imp; but apparently it was not, but a reference to azoth, the alchemists' vital mercury.
During the trails of the witch-hunts in the Middle Ages imps became confused with familiars and both terms were used interchangeably in the trails. Supposedly witches sent imps to do evil deeds against innocence people, in return the witched allowed the imps to suckle their blood through their fingers or protuberances on their bodies. The witch-hunters thus searched witches' bodies for evidence of warts, discolored skin and unnatural lumps that could have served as teats or paps.