As I said I would, I've just gotten done dragging some night creature RAWs out of an uncompressed world.dat, plus searching creature_standard.txt. I haven't checked to see what's new with demons or FBs, as I cut my study version of world.dat down to Night Creatures. (Just checked, and I saw nothing new aside from natural skills.) I'll be modifying this as I uncover more.
Creature Tokens:
[SPOUSE_CONVERTER]: I'm sure it's in some way associated with... well, converting spouses. Figuring out how it works is a task for later. There's no white-spacing in world.dat since it's only meant for machine reading. Bogeymen don't have this.
[SPOUSE_CONVERSION_TARGET]: Creatures with [SPOUSE_CONVERTER] will target these. Goblins lack this.
[NIGHT_CREATURE_HUNTER]: found on all night creatures not named "bogeyman". Presumably sets their tactic type to "hunter," whatever that means.
[NIGHT_CREATURE_BOGEYMAN]: found on bogeymen. Sets their tactic type to "bogeyman"?
[LAIR:(type):(prob)]: presumably determines what sort of lairs this night creature is associated with, with (prob) determining the probability (is it a weight or a probability out of 100? Seems the latter) of that lair being chosen. (type) can be SIMPLE_BURROW, SIMPLE_MOUND, SHRINE, and LABYRINTH as types. Night creatures all have SIMPLE_BURROW and SIMPLE_MOUND, with (prob) of 50 each. Bronze colossi and titans also have SHRINE at 100, and minotaurs have LABYRINTH. Other lair creatures (dragons, hydras, and so forth) have SIMPLE_BURROW.
[LAIR_CHARACTERISTIC:(characteristic):(prob)]: Only case I've seen is [LAIR_CHARACTERISTIC:HAS_DOORS:100] for Night Creatures. A string dump or searching other files should find any other characteristics.
[LAIR_HUNTER]: Found in minotaurs and hydras. Presumably means it will hunt you down if you enter its lair, as opposed to some other behavior (hiding or fleeing?).
[LAIR_HUNTER_SPEECH:(text file)]: Only case I've seen is [LAIR_HUNTER_SPEECH:lair_hunter_minotaur.txt]. Appears to be what the creature says while hunting you in its lair.
[HABIT_NUM:TEST_ALL]: I don't know, I've never seen it in any other format. Precedes all habit lists.
[HABIT:(action):(prob)]: Cannot determine meaning of prob, guessing it's a weight. Actions include COLLECT_TROPHIES, COOK_PEOPLE, COOK_VERMIN, GRIND_VERMIN, COOK_BLOOD, GRIND_BONE_MEAL, EAT_BONE_PORRIDGE, USE_ANY_MELEE_WEAPON, or COLLECT_WEALTH.
[NATURAL_SKILL:(skill):(num)]: As described by Toady One, gives a creature a natural skill. I don't know the scale for (num), but demons have 10 for all (num)s as an example.
[CREATURE_SOLDIER_TILE:(tile)]: Tiles for soldiers of that species.
[SOLDIER_ALTTILE:(tile)] Alt tile for soldiers of that species.
Entity Tokens:
[BUILDS_OUTDOOR_FORTIFICATIONS]: Found on humans. Castle construction?
[BANDITRY:(num)]: Found on humans, goblins, and kobolds; humans and kobolds have a (num) of 10, while goblins have 50! Presumably it says how probable it is a member of the species will turn to banditry.
[LOCAL_BANDITRY]: Found on goblins and kobolds, but not humans. Someone toy with this and figure it out.