Identifying a werewolf is harder than it sounds. A human can have multiple "symptoms" of lycanthropy, yet not be a werewolf. A werewolf can seem completely human except for that one sign that it is, in fact, a wolf. In order to figure out who or what could be a werewolf, you will need to conduct a thorough investigation of the person in question.
Signs in human form
Possibly the easiest way to find out if someone is a werewolf is to wound it while it is in wolf form. The next several days look for a human who has an identical wound. It is best if you can make the wound unique. For instance, if you slice the wolf, try to slice it again in the same spot to make a t, or an x. Whoever bearing the wound will be your wolf.
If a person has several scratches on their hands and face, they could possibly be your werewolf, especially if they do not have a good explanation for those scratches. However, because they have scratches and a bad excuse for them does not automatically mean that they are the werewolf. For all you know, they were cut up exactly as they say.
Other telltale signs are less violent. Physical details can be just as telling as a wound. Looking at the face you would see someone with thick bushy eyebrows, meeting over the nose. The eyes will have the appearance of being dry and capable of reflecting light like a cat's at dusk. Their mouth would be chapped and darker than the average person's, with red or black tinted teeth.
Hands should be the next to be glanced at. The third finger will be as long as the middle finger, if not longer. The fingernails will be long, curved and tinted red. The palms would have evidence of hair. Most werewolves will shave the fur off the palms of their hands, but there will still be some stubble.
Some werewolves, depending on the type, will reveal fur on the inside of a cut.
The wolf form of the werewolf will appear much like other wolves. They are on average much larger than their natural cousins. And they will sometimes travel with their brethren, which can cause some confusion.
A werewolf in wolf form will appear better fed than other wolves. The eyes will appear red or black or reflect light in a shade of red. Unlike the normal wolf, all of their teeth will be sharp and jagged, with the four elongated canines.
In ancient times, the wolf form was claimed to have been easily recognizable by the lack of a tail. Apparently, the werewolf's genes realized the defect and gradually a tail arose from the wolf form. However, the tail could be shorter on a werewolf, for its size, when compared to its brethren.
The half-human half-wolf form will stand out quite drastically no matter the location or its pack. In this form, the werewolf stands easily taller than six feet. It does not matter how tall its human form is. It will be well muscled and covered with fur. With more wolf-like features than human, it is a terror to behold. However, it is more comfortable standing bipedal as a human does, rather than on all fours like its natural cousin.
Once you know how to spot one, the werewolf is pretty easy to pick out of a crowd. The problem is that if the werewolf knows you are looking for it, it could take steps to hide better. So be sure that your hunt is unknown, or you could end up with the lycanthrope chasing you instead of you chasing it.