While researching legends and myths of the Portuguese corredor I came across a fascinating article from 1890. In Portugal, the corredor is also referred to the "night ranger"-- a type of shape-shifting creature that shares many similarities with the European "wehr wolf". The following is a reprint of an article that originally appeared in The Fortnightly Review, which was a popular and influential magazine in 19th century England.
Portuguese Bugaboos: Gloomy Traditional Beliefs Existing Among the Peasants of Portugal
The most somber of the traditionary beliefs in rural Portugal certainly go back to far beyond the time of the Moors, beyond even the period of the entry into the peninsula of the nations from Central Europe. The wehr-wolf legend comes from Roman times. The term for the man-wolf in Portuguese is lobis-homem, hardly a change from the Latin lupus-homo, though it is more than likely that in substance if not in form the lycanthropic myth is far older than the Roman nation itself.
The legend of a human being assuming a wolf's shape is certainly one of the most generally diffused through the world. It takes many forms in Portugal. A common belief is that when there are seven children of the same parents, one, either son or daughter, is fated before the age of puberty arrives to turn into a corredor-- a night-ranger-- that is, to become that which is preliminary to being a true wehr-wolf, or lobis-homem. The corredor need not necessarily assume a wolf's shape; indeed, he often takes that of a hare, a wildcat or a fox, but of nights he must put on the likeness of one of those animals and range through woods and desert places.
The corredor by all I can learn harms no one but himself, and is unconscious of his nightly wanderings as soon as he returns to his human shape and right senses, but he is always to be recognized by excessive leanness, wild eyes, and a pale and haggard face. The corredor steals from his bed, and climbing the highest tree in the neighborhood, strips to the skin and hides his clothes in the branches; then descending naked to the ground, he is instantly transformed into bestial shape, with all the habits belonging to the beast whose form he has put on. He is endowed with supernatural speed and can outstrip man and all other animals.
The child with this fate to undergo passes a novitiate of seven years as a corredor, and then unless the spell is broken he turns into a true lobis-homem, a versi-pellis, a wolf man or a wolf woman. The female of this terrible human wild beast is known as lobeira. Male or female, it is a fierce creature, with appetites exaggerating those of the wolf it resembles, and whose strength and swiftness are greater than those of the wolf. The creature is now no longer harmless, but leaps upon and preys on other animals, and its special delight is in the slaughter and devouring of children.
When once the change into the true lobis-homem or lobeira has taken place I understand that the wolf man or woman can never again be reclaimed into the ranks of our common humanity, but the spell upon a corredor can be broken. It needs but for its clothes to be found and burned, or for blood to be drawn from its body while in the form of the beast; then the spell is broken, the animal returns into human shape-- walking amazed as if from a sleep-walking dream and recovering the reversion of the human soul, of which the true lobis-homem must inevitably forfeit the tenure.
Tales are many where a particularly savage wolf, being sorely wounded by a peasant in a midnight fray, has yet escaped by a seeming miracle. The next morning the unsuspected brother or sister of the peasant himself is seen with a wound of identically the same nature, and so has proved to be nothing less than a foul lobis-homem or lobeira. (The Fortnightly Review)