A witch's familiar has been, in the past, defined as, an animal cursed by the witch that does his/her bidding, usually some poor person who crossed the witch on a bad day. Sorry, wrong definition. A familiar is simply a pet, in my case, the family cat, which has chosen the witch. Yes, it's true, the animal chooses you. Not difficult to understand for those of us who spent all our lives around animals.
A familiar can by the typical cat, but nearly any animal will do. Pleas remember, let the animal chose. You would force a fellow human to perform magick with you, please give the same respect to our animal friends. If they are allowed to, let them walk around your ritual area, in and out of your circle {if you don't mind}, and let them sniff your tools. Open your heart, your mind, and your ears and you may be amazed to find that your pet is speaking to you. *gasp*
I know many people may find this hard to believe. They are not going to open their whiskered faces and say, "Hey Joe, what's up?" They use telepathy so a picture or thought my pop into your head from no where.
It is wonderful to work with a familiar. If you are a solitary, it's a way to help with some of the loneliness. But even if you don't work alone, a familiar is a wonderful friend.