What can familiars be?

Familiars are spirits or entities. They choose you because it's a type of spiritual bond between them and yourself

Sometimes they take animal forms as well, but still choose you and bond with you.

My pet cat acts as my familiar.

I'm not sure where the idea that a pet is the same as a familiar came from. I guess I have to blame it on some of the crop of poorly researched books on the market these days. But the fact of the matter is that our beloved pets and a Witch's familiar are very, very different things.

A Witch's familiar is an animal spirit or a magical construct created by the Witch or the Magician as an adjunct to their magical workings, as a repository for power, and if needed as a defense against magical attack from another magic user. A Witch or a magician can draw upon the energies of the familiar when they need an extra boost of energy in a magical working. Conceivably if the spell is important enough, the Witch could completely drain the familiar of energy causing it to "die" or cease to exist. And in the case of a magical attack, the attack could be diverted to the familiar so that it would be the familiar which is destroyed rather than the magic user. None of these are things that I think any of us would want to do with our pets.

There is an excellent article on familars here: http://en.wikipedia.org/wiki/Familiar_spirit

Animals are very sensitive to the energies around them and they may be drawn to us when we are working magic because they can sense the energy. They also want to be around their people, which again will make them want to be where we are..and that may be where we are doing magic. Neither of these things makes the animal a familiar or inherently magical in and of itself.

Ok cool thanks. New question: I don't have any pets, so how would I get a familiar to choose me?
I see a lot of people saying "you have to meditate on it" but what exactly do you meditate on?

Familiars are spirits. I like to use the word familiar because the word history means that it's related with the word "family" and it really feels like that, I must admit, even more than my horribly abusive earthly family.

And you can even take the word "familiar" and its common non-magic meaning, which is something that you recognize from before, and that's what it also feels like.

So, what I call "familiars" are not physical, and are not animal-shaped.

You can imagine sitting someplace and waiting for something or someone to surprise you who seems to be friendly, but...if it's not time for them to reveal themselves to you, then they won't do so.

Just because a pet and a familiar are two different things, doesn't mean that you can't make a pet into a familiar. As stated, a familiar is a repository of power for the witch. Animals, being sensitive to the magic, is actually one of the easiest ways to MAKE a familiar. And, the added benefit of not dying on you should you need larger pools of energy.

I would NEVER use Amelia to take the brunt of a magical blow meant for me, I have Thoughtforms and Wards set up for THAT eventuality.

Awesome. Thanks a ton, it really helped

Pets cannot be made into familiars as familiars are energy constructs and pets are physical beings. They are quite different in nature and in use.

The first magic tutorial that I ever followed, that actually got me to progress in magic, actually described a process wherein you create a construct and then embed it in an embryo of your chosen animal .

...I actually thought that part was a little uncomfortable to read. This was supposedly a beginner's magic tutorial.

But...Lark, I believe it's possible. It might not be ethical, whatever that would mean in this context, but it's possible.

It's only unethical if you treat the animal in question like you would a pure thoughtform familiar, IE: you use it as a shield.

I don't use Amelia as a shield. She merely helps me be freely providing energy. You may think it's strange, but, on an emotional level, an animal that bonds with you can be just as useful as any thoughtform. More so, especially when it comes to cats and certain larger birds, who are smarter then the rest of the animal kingdom.