Quick Characters

While players will likely appreciate the ability to customize their character to be a complex being with various strengths, weaknesses, and quirks. For most characters, however, it is likely not worth going into the same amount of detail as for a player character. The quick character system provides a faster, simpler, and more efficient system for making a character sheet for the new player who just showed up and doesn't have a character sheet, for NPC's, for enemy characters, and for minions the players summon or creatures they transform into.

High Stats and Low Stats

The first two things you need to build a quick character are a high stat and a low stat. The high stat is a number, usually from 2-7, which represents everything the character excels at. The low stat is usually half the high stat rounded up, and represents everything the character is proficient in, but not great at.
So for example, a hawk would use its high stat for tasks like seeing, flying, and attacking prey. It would use its low stat for hearing, resisting disease, and navigating the wilderness. It would not be capable of making a table or chair, so wouldn't bother to roll for those tasks, and it would have a 0 for things like Strength or sense of smell, which are minimal.

Health

Health for quick characters is determined by their size class and their high stat if they have particularly strong constitutions or their size class and their low stat if they are weaker. For exammple, while a wolf and a bear are the same size class, the Bear would use its high stat to calculate Health while the wolf would use its low stat.
The chart below lists size classes, the approximate length/height that corresponds to that size class, and the formula for determining Health at that size class.
Tiny (less than 1 foot): stat, 1 damage
Small (1 foot to 1 yard): 3 + 1x stat
Regular (1-3 yards): 10 + 2x stat
Large (3-10 yards): 20 + 3x stat
Gargantuan (10-30 yards): 40 + 4x stat
Colossal (30-100 yards): a creature of this size is not going to be harmed by the weapons a human will bring to bear against it.

Spirit

Spirit for a creature is usually half the formula for Health, though the character may use high stat for one but low stat for the other.

Other Stats

Damage dealt by regular size creatures is usually 2x either its high stat or low stat. If the being is particularly magical, it might have a Magic Power equal to its low stat. Speed and Range are usually no higher than the low stat, and might be even lower. Only creatures with abilities far beyond that of a human will have a Speed or Range any higher.

Damage Reduction

Characters who have armor will get damage reduction from that. Creatures below regular size will rarely have damage reduction, though an ordinary crab or turtle might get 1. Human characters can usually get 1-3 damage reduction, and so damage reduction equal to the character's low stat isn't unreasonable. Bigger creatures might have more.
Note to GM's: Damage reduction can quickly become a very powerful tool. Even a seemingly small increase in damage reduction can make a creature vastly more difficult to kill. To that end, you should be careful about giving too much of it to your monsters, and about allowing your players to get too much of it as well.