Familiars

The art of summoning and binding a familiar was discovered long ago by ancient arcanists.  If some Archaian sources are to be believed, familiars predate even their long eroded civilization.
To summon a familiar one must be able to channel magic in a small ritual, whether this be through mastery of the Silver Sea or with the aid of a more powerful entity.  The ritual takes about an hour, during which the caster must burn various herbs, incense, and charcoal in a brass brazier while speaking a series of phrases and incantations paired with the correct gestures.  These phrases and gestures change depending on where the caster wishes to draw the familiar from and what form they wish them to take.  A familiar can be pulled from any of the five planes, but binding one from the Mortal Plane is by far the easiest.  When creating a familiar from the Mortal Plane, a creature is created from raw magical energy, but when a creature is drawn from one of the other planes, its soul resists.
Although extradimensional familiars are harder to bind, they are significantly stronger than ones from the Mortal Plane.  Some examples of extradimensional familiars include: Imps, Quasits, Faerie Dragons, Pseudo Dragons, Fairies, and Shadow Ravens.