A familiar is an animal chosen by a spellcaster to aid him in his study of magic. It retains the appearance… and abilities of the normal animal it once was, but is now a magical beast…If a familiar is lost or dies, it can be replaced … through a specialized ritual… that takes 8 hours to complete.
What happens to familiars if the wizard dies? When a surviving familiar outlives his bonded wizard, sometimes the familiar-bond is strong enough that the familiar remains behind even after the wizard’s death; it just passes to an heir or a close relative, the family or guild organization of the deceased wizard.
Living symbols of the deceased wizard, the wizard-familiar is treated with care and respect but is more or less an intelligent pet, magical beast in fact with one very useful ability: it can reliably carry messages over long distances and return with a reply if there is any. Often times this is a raven or owl but sometimes a cat, bat or even toad can and will tenaciously retain the familiar-bond and continue on to serve another.