Lycanthrope

Lycanthropes, otherwise known as Werewolves, are a sub-race of Earth Ponies who possess a small part of the soul of Lycan (the Alicorn of the Moon who was killed by Discord). They appear as normal ponies until their transformation is triggered, whether it is magically invoked by Luna or another user of the Moon control spell or called upon by the user. At this point they transform into a form resembling a combination of their original form and that of a Wolf.

A Lycanthrope's Aura is expressed during the transformation process, and has a minor effect on the appearance of the transformed form.

Gameplay wise, Lycanthrope's are considered to be Earth Ponies until they transform.

Personality
Lycanthropes have as varied personalities as non-Lycanthrope Earth Ponies, but have a few traits which they all share.

Firstly, their personality is more like that of a wolf; Lycanthropes often develop a "pack mentality", causing them to consider themselves or another companion as the "alpha" of any group, and treat them accordingly. They also begin to show other minor mannerisms and behaviours typical to wolves.

Due to a part of Lycan's soul being merged with their own, all Lycanthropes have an innate desire to perform Lycan's will; this includes the protection of the princesses Celestia and Luna, and the destruction of Discord and the other Draconequus who killed Lycan. This desire can be overcome, but many Lycanthropes feel a sense of loyalty to Lycan for granting them their power.

Magic
In addition to their Earth Pony magic, Lycanthropes have an innate magical ability to communicate better with wolves and any sub- or related species, magical or otherwise, such as Timber Wolves. This often, but not always, correlates to the Husbandry ability.