First, the original meaning or function of a witch’s familiar was a familiar spirit. Meaning, not a physical (at least not corporeal like the ‘real world’ we inhabit) form.
At some point in the last century or so, it appears that the term ‘familiar’ has been applied to just any random animal that hangs around a witch’s place, including family pets.
History of Witches’ Familiars
This is one of those things that there are entire books written about it, and I encourage you to go read those, because this post is more of a brief exploration to clear the air and whet your appetite, should you want to learn more.
You can read of familiars mentioned in texts dating back to the medieval period, including accounts of witch trials, interrogations by the clergy, and the Lesser Key of Solomon, in which various of the goetic demons are mentioned as ‘giving good familiars.’ That was written down around the 17th century, but came from sources thought to be recorded during possibly the 15th century.
Before that, there is a good deal of culture-specific lore passed down mostly verbally in many spiritual practices around the world referring to familiar spirits. Most written accounts of familiars begin around the 15th century, however.
All of these sources, however, agree that familiars are spirits. They are spirit companions that aid a witch in magickal or spiritual workings. They may act as a form of spirit guide at times, as well as a source of information and even energy, when needed.
Some familiars can even go find or retrieve items for you, if they are given such a purpose, and there’s some overlap with servitors in this regard.
Familiars are also not limited to appearing as animals, and can appear as human-looking, alien-looking, or other forms. This may depend on the nature or origin of the familiar and also probably has a significant influence from the spiritual and cultural practices of the witch herself.
It seems that the association with pets or physical animals began with neo-modern practices, especially Wicca, which makes it a wholly modern construct.
Purpose of a Familiar
As mentioned above, the familiar spirit is not a pet, but a companion of assistance and protection. Often the familiar spirit is sent to or given to a witch to protect them, assist them, or warn them when something harmful is about to happen, or even if a curse or hex has been thrown their way.
Familiars can be called by the witch, or can be given or assigned to the witch by another spirit, such as a spirit guide, an ancestor, or even a deity, if the witch asks for one.
Familiars are also usually assigned for a specified length of time, such as a few weeks for a specific task, or many years or decades to fulfill a much broader purpose in the witch’s life. This may or may not involve a pact between the witch and the familiar spirit.
The main difference between the familiar and a servitor here is that the servitor is created by the witch of her own energy and the familiar is an external spiritual entity. You can read more about servitors and how to create them here.
Some familiars are strictly for divinatory purposes to send information or warnings to the witch, or to provide insight into questions asked during divination sessions.
Familiars may appear visibly to the witch, but most commonly, they are said to communicate psychically through visions and dreams, or while the witch enters a trance state or visits the astral.
But, Is My Pet My Familiar?