Homunculus
A Homunculus (plural: Homunculi) is a type of artificial lifeform that is created by unnatural means, such as magic or by modifying an already existing living creature. They are distinct from other types of magically-induced creatures, such as the undead or Youkai, in that they are not reanimated or summoned; instead, they are created solely through such means.
Creation
Creation of a homunculus is accomplished by one of two ways; either rousing through materials and magic, or by altering an already living creature to change them significantly.
The former type is created by fashioning a generic shell from natural materials, such as metals, oils, etc. into a humanoid form. This generally requires a great deal of skill, not just in achieving the right balance of the ingredients, but also carefully balancing the shape and form of the shell. From there, the 'spark of life' is infused in the shell via a complex magical ritual, which uses divine energies from dead Gods, or via necromatic-like soul-splicing and/or merging, in order to create a new soul to inhabit the vessel.
Modified lifeforms are done via mutating existing creatures, such as an animal, with magical or divine energies, alchemic compounds, or divine energies from dead primal Gods. Alternatively, although much more risky, they can be created by fusing such creatures with another lifeform, such as a mortal.
It should be noted that Homunculus creation is viewed as taboo in most city-states at best, and completely immoral and illegal at worse -- such as in the case of Chimera and Amalgama types. Salamandra are likely more tolerated, yet are still discouraged, especially by Karaten and in towns with Mage's Guilds.
Lifespan
The lifespan of a homunculus widely varies depending on the quality of its creation. The general minimum and maximum range for successful creations range between 10 years and 200 years. In theory, however, homunculi can be maintained and be potentially immortal, provided they do not receive irreparable damage.
Physiology
Homunculi physiology varies, but in general, they are very similar to normal mortals by design. They may eat, sweat, cry, bleed, and so on. Although artificial, their bodies still contain necessary vital organs, such as a brain, heart, lungs, etc. They require nourishment in order to sustain their bodies and refill their Focus, but depending on the type, they may be capable of consuming and digesting things normal races may not, such as blood, magical rocks, etc. Similarly, unless otherwise noted, they must breathe.
Homunculi naturally heal from wounds over time, and are also somewhat more resistant to disease due to their artificial bodies. For the same reason, while they are affected by healing magic, its effects are diminished. A homunculi which is destroyed or killed cannot be revived, even if a new body is prepared, or the existing one has attempts to 'repair' it made.
Homunculi blood is especially nourishing to vampires due to its high focus content.
Intelligence
The personality and temperament of a homunculi is unpredictable, and cannot be controlled, generally. There is a very real threat of a created homunculus turning on their creator, even as soon as just after being created.
Once created, homunculi begin life with a level of intelligence appropriate to the parts used and the creation method - even those created without fusing lifeforms. While the details of why this occurs is unknown, it is theorized that the magical nature of their birth allows them to draw this initial knowledge directly from the Akashic Record; this is one of the major reasons why homunculi generate so much interest for mages. They may also gain parts of the knowledge and memory of their creator through osmosis, by way of their involvement in the ritual that creates them. This occurs at random and is not preventable, but does not always happen.
Reproduction
Capability for reproduction wildly varies depending on the method of creation. Typically, only fusion-based homunculi can reproduce, and only with species they were compatible with before fusion. Since the homunculi's body is magical, the progeny will never be a homunculi, and always the race of their partner. Homunculi can never create offspring with other homunculi.
Souls
Homunculi have souls, which are created by the divine energies that fashioned them, or via a fusion of subjugated souls. When they expire, their souls go to Lazarus, as per normal.