In the set Ancient Chronicles: Chaotic Familiars players can find these intelligent little creatures that are able to create a magical link with their humanoid friends.
The ancient scrolls of the Archmagi classify Chaotic familiars into three types, each characterized by a deep bond with their owner: Domestic (Cat, Crow); Wild (Bat); Legendary (Drakeling, Imp). Each of these Familiars provides valuable help on the battlefield or grants peculiar abilities to its owner, such as the life-drinking of an Imp, or the poisonous spittle of a Drakeling. But this deep bond has a downside. When a Familiar dies, its owner suffers a terrible mental shock, which hampers their skills for a time.
This expansion can be used with any Sword & Sorcery Quest or Campaign (Immortal Souls or Ancient Chronicles), by simply shuffling the Familiar cards into the Treasure deck.