Bestiary Start

Humankind:

Mundane
Most of the population, the regular humans that make up most of the planet. Not a whole lot to say, but everyone has at least enough magic drawn to them by being alive to use magical wards and if they pass other qualifications, magical artifacts left by old gods.

Undead
Comes in a variety, there are numerous ways a person can fail to completely shed the mortal coil. For details on various types see Monsters section.

Mage
A human being with a large enough magical sphere of influence that they're able to learn to control magical power. Magic requires mental agility and creativity to use to its best potential, but those traits don't always line up with those who have the most power. Elemental mages focus on the classical elements of lore, usually with a preference to one in particular and Light mages focus on healing and protection. Their power is largely agreed to derive from the alternate realm of Faerie through unknown means.

Augment
A transmission from space carrying instructions on how to modify the human genetic code in ways that were decades ahead of the science at the time hits the earth. Only a handful of facilities and persons were able to make any use of it, but the results were striking. Augments are few in number, but their utter physical superiority and daunting mental capacities make them formidable and egotistical. Interestingly they are the only variant of humankind completely unable to utilize magic.

Mixed Blood:
Some creatures from both the Faerie and Monster categories can crossbreed with normal humans. These hybrids vary radically depending on their ancestry.

Void Mage
Sometimes people get lost in the alternate realm of Nightmare and sometimes their body comes back, driven by some terrible force from the depths of the hellish realm. There is a fairly solid case for filing this under either undead or monster because the body only used to be human.

The Fair Folk:

Pixies

Faries

Nymphs

Siren
Dreaded for good reason, the mere sound of their voice can put people under a powerful spell. Countless humans across the ages threw themselves into nearly certain death at the sound of a siren's call. There are a few variants, but the sea and shore dwelling types are the most populous in any era. Naturally gifted in music of all sorts, they often use that talent to amplify the range of their vocal induced trances.

Sidhe
"Let me just say this, if you call one of the Sidhe a 'fairy'... I do not know you." - Circe

Monsters:

Gremlin
Among the very least threatening of supernatural menaces in a physical confrontation, they're still best not taken lightly. They instinctively understand whatever technology they come across and love to make it go wrong in whatever way seems amusing at the time. It's worth noting that what they find amusing is generally in the area of murderous mayhem. Have a particular fondness of making military aircraft crash.

Ghoul
Basically on the low end of the predation hierarchy, they scavenge at least as much as they hunt. About human strength and averaging only slightly faster, they lack the physical superiority of most supernatural monsters. They prefer sneak attacks and are unlikely to want to fight a mage head-on unless pressed by something a little higher up the hierarchy.

Elder Ghoul
In the odd event a ghoul exists long enough to be considered old it will grow in power like most supernatural beings, but unknown to the heroes of the story they never exceed an "almost olympian" level on their own. In order to become the 50mph running, car flinging menaces seen in the story they have to be chosen and empowered by a evil mage, most often a vampire, as a personal attack dog. Once freed of their master though by whatever means, they often go on to lead a group of lesser ghouls.

Succubus
Of the various creatures that might seduce a person to their untimely demise, the succubus and incubus are on the top of the pecking order. They constantly emit a glamour that works on perceptions, making them seem more attractive, and even more reasonable than they are. It's natural to want to please one of these creatures after any length of contact.

Fishman
Pretty much what it sounds like, the creature from the Black Lagoon is a silly old depiction of something like this creature. They tend to be carnivorous attacking the physically weaker beach goers. Sometimes there's a squicky sort of confusion when they have a tendency to attack humans of the other gender, they feel an attraction but their beastly instincts translate that into an attack and eat reflexes.

Vampire

Werewolf
Technically they come in a few variants. One is the classic transmittable monster transformation that coincides with the full moon. The effect is strongest during the full moon but the transformation occurs on the night preceding and after as well.
Second is a will-based shifter. These aren't nearly as powerful in their beast form, but can enter it at will. Their wolf form strongly affects the psyche over time.
The third are permanently monstrous, only able to take a passably human form for short periods of time. They are believed to have some kind of connection to Fenrir and are among the more formidable monsters.

Fear Phantom

Dragon

Leviathan