I will clarify my expectations about the design of familiars here, because that is not something that applies to a single player or character.
When a player proposes a magical animal that will eventually be bound as a familiar, I want to see the following steps:
- The stats it would have as a mundane animal. If possible, use one of the mundane animals already described in the Book of Mundane Beasts (RoP:M p.140 and HoH:MC p.40) as a base. If an already-defined animal is close to the one you are aiming at, use that and tweak it a little. For example, a crow or raven wouldn't be very much different from a falcon -- the crow is a bit smaller (while a raven might have the same Size), switch a few qualities around (Crafty and Vocal instead of Keen Eyesight and Pursuit Predator). When you make such changes, explain them.
- The detailed and explicit process of turning the mundane animal into a magical animal (concept, season, unmodified Might, etc.) Since this is now a magical animal, the magical animal must have the virtues, flaws, and abilities of the mundane animal before we get to add more. They must still be paid for, but they are mandatory. For the rest of the selections, explain each choice as you go.
Step 1 should be validated and agreed upon before proceeding to step 2.
At the beginning of step 2, check with the troupe on your assumptions and decisions before proceeding with detailed selection of magical qualities and inferiorities, and again for the design of magical powers. Concept becomes very important for those.
Here's an example. Clusius might be interested in binding a magical Rottweiler. Luckily for me, there are already stats for a Hound.
Characteristics: Cun 0, Per +2, Pre –4, Com 0, Str 0, Sta +2, Dex +1, Qik +2
Size: 0
Confidence Score: 0
Virtues and Flaws: Improved Characteristics, Long-Winded, Sharp Ears, Reckless
Qualities: Domesticated, Keen Sense of Smell, Pack Animal, Pursuit Predator, Vocal
Personality Traits: Loyal +3, Reckless +3, Brave +2
Combat: Bite: Init +2, Attack +8, Defense +7, Damage +1
Soak: +2
Fatigue Levels: OK, 0/0, –1, –3, –5, Unconscious
Wound Penalties: –1 (1–5), –3 (6–10), –5 (11–15), Incapacitated (16–20), Dead (21+)
Abilities: Athletics 3 (distance running), Awareness 3 (keeping watch), Brawl 3 (bite), Hunt 4 (track by scent)
Natural Weapons: The weapon statistics for a dog’s bite are Init 0, Atk +3, Def +1, Dam +1.
Now, the Rottweiler is known for its powerful jaw, so I might make a case for adding the Large Teeth quality. It is also a tough fighter, so I could suggest adding the Tough (or Enduring Constitution) virtue balanced with the Oversensitive flaw (against those displaying agressivity towards their master).
But the troupe may judge these to be unecessary. After all, the description for the Hound already states that such large dogs include the Rottweiler.
Then I would proceed with turning the mundane animal into a magical one. I would propose switching out the Pack Animal mundane quality in favour of Pack Leader. That makes sense and comes free. Meaning a "free" obligation to purchasing 1 more point of Com and Leadership 5 in the design of the magical animal -- I still pay for those!
With those changes, the basic Abilities package of a Hound would cost my magical animal 215 xp. The Hound already has 3 virtues and 1 flaw, so I am limited in my additional choices. As a grog-level character this means I need to pick 2 more flaws and cannot add additional virtues. If this was a companion-level character then I could pick up to 4 more virtues and flaws. I also add the free virtue Magical Animal.
As a concept, I decide that this Rottweiler was one of the first to be breeded by the Romans when they came to Germany, its father having been matched by a local dog into a superior breed of guard dogs. It was lost to the Romand during a battle in a magical regio that it was unable to escape after the Roman legion it was with was massacred in the Black Forest. Its ongoing exposure to the magic of the regio slowly transformed it into a magical creature, gaining intelligence and eventually escaping the regio. It has gathered stray dogs over the years, forming a pack that roams the forests of Germany, moving from place to place.
I decide this is a grog-level character, so I add the flaws Wrathful (minor) and Craving for Travel (Grogs p.78). I also decide on a Might of 5, the "standard" Might for a grog-level magical creature in a High-powered saga. Considering the need for enough xp to purchase the basic Abilities package of the mundane animal, I must select at least Summer as a season (up to 360 xp). I make a case that the hound could very well be at Autumn (up to 720 xp), being one of the direct descendant of the hounds brought by the Romans centuries ago. The troupe decides that my case for it being Autumn is a bit weak, but finally agrees.
And then I move on to magical qualities and inferiorities. What makes sense for this magical hound? Perhaps Animal Resistance, Improved Attack, Improved Soak, Lesser Power and Minor Virtue (Reserves of Strength). I also select the Susceptible to Deprivation magical inferiority, which allows me to add a Personal Power.
All I need to do now is decide what powers make sense for a magical hound...