Note: Do not rely on this information. It is very old.
Ichneumon, any individual of the genus Herpestcs, of the Civet family, with twenty-two species from Asia and Africa, one straying into Spain. They resemble weasels in form, but are of larger size, and feed on small mammals, reptiles, poultry, eggs, and insects. The Egyptian Ichneumon (H. ichneumon), rather less than three feet long, has grey fur, and the muzzle and paws black. It has long been domesticated, for killing rats and mice, and was venerated by the ancient Egyptians. The so-called Andalnsian variety is identical. The Mongoose (H. griseus), an Indian species, is rather smaller.
It is a, great destroyer of serpents, but the stories told of its seeking a remedial herb when bitten are fabulous.