Friendly Giant Spiders... >.>
Of all the things... But yea, just take one of the default spiders... make entities with em, copy and paste the dwarf entity to make it easy and them friendly/compatible.
Delete alot of the jobs/weapons/armors... Then they'd only make silk and arachnoid clothes. Unless there are certain other things you want/expect of this spider civilization...
I might do this later tonight for ya if I remember to.
EDIT:
Entity
entity_arachnoid
[OBJECT:ENTITY]
[ENTITY:ARACHNOID]
[CREATURE:ARACHNOID]
[trANSLATION:DWARF]
[DIGGER:ITEM_WEAPON_PICK]
[ARMOR:ITEM_ARMOR_PLATEMAIL:COMMON]
[ARMOR:ITEM_ARMOR_CHAINMAIL:COMMON]
[ARMOR:ITEM_ARMOR_LEATHER:COMMON]
[ARMOR:ITEM_ARMOR_COAT:COMMON]
[ARMOR:ITEM_ARMOR_SHIRT:COMMON]
[ARMOR:ITEM_ARMOR_CLOAK:COMMON]
[ARMOR:ITEM_ARMOR_TUNIC:COMMON]
[ARMOR:ITEM_ARMOR_TOGA:UNCOMMON]
[ARMOR:ITEM_ARMOR_VEST:COMMON]
[ARMOR:ITEM_ARMOR_DRESS:COMMON]
[ARMOR:ITEM_ARMOR_ROBE:COMMON]
[HELM:ITEM_HELM_HELM:COMMON]
[HELM:ITEM_HELM_CAP:COMMON]
[HELM:ITEM_HELM_HOOD:COMMON]
[GLOVES:ITEM_GLOVES_GAUNTLETS:COMMON]
[GLOVES:ITEM_GLOVES_GLOVES:COMMON]
[GLOVES:ITEM_GLOVES_MITTENS:COMMON]
[SHOES:ITEM_SHOES_SHOES:COMMON]
[SHOES:ITEM_SHOES_BOOTS:COMMON]
[SHOES:ITEM_SHOES_BOOTS_LOW:COMMON]
[SHOES:ITEM_SHOES_SOCKS:COMMON]
[PANTS:ITEM_PANTS_PANTS:COMMON]
[PANTS:ITEM_PANTS_GREAVES:COMMON]
[PANTS:ITEM_PANTS_LEGGINGS:COMMON]
[SHIELD:ITEM_SHIELD_SHIELD]
[SHIELD:ITEM_SHIELD_BUCKLER]
[SIEGEAMMO:ITEM_SIEGEAMMO_BALLISTA]
[trAPCOMP:ITEM_TRAPCOMP_GIANTAXEBLADE]
[trAPCOMP:ITEM_TRAPCOMP_ENORMOUSCORKSCREW]
[trAPCOMP:ITEM_TRAPCOMP_SPIKEDBALL]
[trAPCOMP:ITEM_TRAPCOMP_LARGESERRATEDDISC]
[trAPCOMP:ITEM_TRAPCOMP_MENACINGSPIKE]
[TOY:ITEM_TOY_PUZZLEBOX]
[INSTRUMENT:ITEM_INSTRUMENT_DRUM]
[CLOTHING]
[SUBTERRANEAN_CLOTHING]
[CURRENCY_BY_YEAR]
[CURRENCY:COPPER:1]
[CURRENCY:SILVER:5]
[CURRENCY:GOLD:15]
[SELECT_SYMBOL:WAR:NAME_WAR]
[SUBSELECT_SYMBOL:WAR:VIOLENT]
[SELECT_SYMBOL:BATTLE:NAME_BATTLE]
[SUBSELECT_SYMBOL:BATTLE:VIOLENT]
[SELECT_SYMBOL:SIEGE:NAME_SIEGE]
[SUBSELECT_SYMBOL:SIEGE:VIOLENT]
[SELECT_SYMBOL:ROAD:NAME_ROAD]
[SELECT_SYMBOL:TUNNEL:NAME_TUNNEL]
[SELECT_SYMBOL:BRIDGE:NAME_BRIDGE]
[SELECT_SYMBOL:WALL:NAME_WALL]
[SELECT_SYMBOL:REMAINING:ARTIFICE]
[SELECT_SYMBOL:REMAINING:EARTH]
[CULL_SYMBOL:ALL:DOMESTIC]
[CULL_SYMBOL:ALL:SUBORDINATE]
[CULL_SYMBOL:ALL:EVIL]
[CULL_SYMBOL:ALL:UNTOWARD]
[CULL_SYMBOL:ALL:FLOWERY]
[CULL_SYMBOL:ALL:NEGATIVE]
[CULL_SYMBOL:ALL:UGLY]
[CULL_SYMBOL:ALL:NEGATOR]
[STONE_PREF]
[INDOOR_FARMING]
[USE_CAVE_ANIMALS]
[USE_ANIMAL_PRODUCTS]
[COMMON_DOMESTIC_PACK]
[COMMON_DOMESTIC_PULL]
[COMMON_DOMESTIC_MOUNT]
[COMMON_DOMESTIC_PET]
[USE_MISC_PROCESSED_WOOD_PRODUCTS]
[EQUIPMENT_IMPROVEMENTS]
[ART_IMAGE_ELEMENT_MODIFIER:PLANT:64]
[ART_IMAGE_ELEMENT_MODIFIER:TREE:64]
[ITEM_IMPROVEMENT_MODIFIER:RINGS_HANGING:64]
[ITEM_IMPROVEMENT_MODIFIER:BANDS:384]
[ITEM_IMPROVEMENT_MODIFIER:SPIKES:384]
[ADVENTURE_TIER:3]
[FRIENDLY_COLOR:1:0:1]
[DEFAULT_SITE_TYPE:CAVE_DETAILED]
[liKES_SITE:CAVE_DETAILED]
[TOLERATES_SITE:CITY]
[TOLERATES_SITE:CAVE_DETAILED]
[LEADER_TYPE:KING]
[SITE_LEADER_TYPE:STANDARD]
[START_BIOME:MOUNTAIN]
[BIOME_SUPPORT:ANY_FOREST:1]
[BIOME_SUPPORT:MOUNTAIN:5]
[BIOME_SUPPORT:ANY_GRASSLAND:1]
[BIOME_SUPPORT:ANY_SAVANNA:1]
[BIOME_SUPPORT:ANY_SHRUBLAND:1]
[BIOME_SUPPORT:ANY_RIVER:1]
[PROGRESS_TRIGGER_POPULATION:1]
[PROGRESS_TRIGGER_PRODUCTION:1]
[PROGRESS_TRIGGER_TRADE:1]
[DIPLOMAT]
[MERCHANT_NOBILITY]
[DIPLOMAT_BODYGUARDS]
[MERCHANT_BODYGUARDS]
[ACTIVE_SEASON:AUTUMN]
[AMBUSHER]
[MAX_STARTING_CIV_NUMBER:3]
[START_GROUP_NUMBER:75]
[MAX_POP_NUMBER:300]
[MAX_SITE_POP_NUMBER:150]
[RELIGION:PANTHEON]
[RELIGION_SPHERE:FORTRESSES]
[RELIGION_SPHERE:JEWELS]
[RELIGION_SPHERE:METALS]
[RELIGION_SPHERE:MINERALS]
[RELIGION_SPHERE:MOUNTAINS]
[RELIGION_SPHERE:WEALTH]
[MAYOR]
[WANDERER]
[BEAST_HUNTER]
[SCOUT]
[PERMITTED_JOB:MINER]
[PERMITTED_JOB:CARPENTER]
[PERMITTED_JOB:WOODCUTTER]
[PERMITTED_JOB:ENGRAVER]
[PERMITTED_JOB:MASON]
[PERMITTED_JOB:ANIMAL_CARETAKER]
[PERMITTED_JOB:ANIMAL_TRAINER]
[PERMITTED_JOB:HUNTER]
[PERMITTED_JOB:WOODCRAFTER]
[PERMITTED_JOB:STONECRAFTER]
[PERMITTED_JOB:WEAVER]
[PERMITTED_JOB:CLOTHIER]
[PERMITTED_JOB:FISHERMAN]
[PERMITTED_JOB:FISH_DISSECTOR]
[PERMITTED_JOB:FISH_CLEANER]
[PERMITTED_JOB:CHEESE_MAKER]
[PERMITTED_JOB:MILKER]
[PERMITTED_JOB:COOK]
[PERMITTED_JOB:THRESHER]
[PERMITTED_JOB:MILLER]
[PERMITTED_JOB:BUTCHER]
[PERMITTED_JOB:TANNER]
[PERMITTED_JOB:DYER]
[PERMITTED_JOB:BREWER]
[PERMITTED_JOB:SIEGE_ENGINEER]
[PERMITTED_JOB:SIEGE_OPERATOR]
[PERMITTED_JOB:PUMP_OPERATOR]
[PERMITTED_JOB:CLERK]
[PERMITTED_JOB:ADMINISTRATOR]
[PERMITTED_JOB:TRADER]
[PERMITTED_JOB:ARCHITECT]
[WORLD_CONSTRUCTION:TUNNEL]
[WORLD_CONSTRUCTION:BRIDGE]
[WORLD_CONSTRUCTION:ROAD]
[ETHIC:KILL_ENTITY_MEMBER:PUNISH_CAPITAL]
[ETHIC:KILL_NEUTRAL:ONLY_IF_SANCTIONED]
[ETHIC:KILL_ENEMY:ACCEPTABLE]
[ETHIC:KILL_ANIMAL:ACCEPTABLE]
[ETHIC:KILL_PLANT:ACCEPTABLE]
[ETHIC:TORTURE_AS_EXAMPLE:UNTHINKABLE]
[ETHIC:TORTURE_FOR_INFORMATION:UNTHINKABLE]
[ETHIC:TORTURE_FOR_FUN:UNTHINKABLE]
[ETHIC:TORTURE_ANIMALS:UNTHINKABLE]
[ETHIC:TREASON:PUNISH_CAPITAL]
[ETHIC:OATH_BREAKING:PUNISH_CAPITAL]
[ETHIC:LYING:PERSONAL_MATTER]
[ETHIC:VANDALISM:PUNISH_SERIOUS]
[ETHIC:TRESPASSING:PUNISH_SERIOUS]
[ETHIC:THEFT:PUNISH_SERIOUS]
[ETHIC:ASSAULT:PUNISH_SERIOUS]
[ETHIC:SLAVERY:PUNISH_CAPITAL]
[ETHIC:EAT_SAPIENT_OTHER:UNTHINKABLE]
[ETHIC:EAT_SAPIENT_KILL:UNTHINKABLE]
[ETHIC:MAKE_TROPHY_SAME_RACE:APPALLING]
[ETHIC:MAKE_TROPHY_SAPIENT:SHUN]
[ETHIC:MAKE_TROPHY_ANIMAL:ACCEPTABLE]
[WILL_ACCEPT_TRIBUTE]
Creature *Don't use this one.*
creature_arachnoid
[CREATURE:ARACHNOID]
[NAME:arachnoid:arachnoids:arachnoid]
[TILE:'S'][COLOR:7:0:0]
[MODVALUE:10]
[LARGE_ROAMING][FREQUENCY:20][DIFFICULTY:3]
[EXTRACT:giant cave spider venom:7:0:0]
[EXTRACT_VALUE:100]
[EXTRACT_PARALYZE][NATURAL]
[EXTRACT_ANTIDOTE:giant cave spider antivenin:7:0:0:100]
[WEBBER][THICKWEB][WEBIMMUNE][AMBUSHPREDATOR][PARALYZEIMMUNE]
[LARGE_PREDATOR]
[GENPOWER:4]
[BLOODTYPE:W][CHITIN]
[GRASSTRAMPLE:10]
[CARNIVORE]
[NOPAIN][EXTRAVISION][NOSTUN][NOEMOTION][NOSKULL][NOBONES]
[BUILDINGDESTROYER:1]
[NOFEAR]
[PREFSTRING:mystery]
[BODY:SPIDER:2EYES:HEART:GUTS:BRAIN:MOUTH]
[SIZE:10]
[MAXAGE:200:300]
[ATTACK:MAIN:BYTYPE:MOUTH:bite:bites:1:6:GORE][ATTACKFLAG_CANLATCH][SPECIALATTACK_INJECT_EXTRACT:50:100]
[BABY:1][CHILD:5]
[FAT:1]
[NO_SLEEP]
[ALL_ACTIVE]
[POPULATION_NUMBER:3:5]
[BIOME:SUBTERRANEAN_CHASM]
[HOMEOTHERM:10040]
[STANDARD_FLESH]
.... Frell! No wonder why I have no Giant Cave Spiders! They gots no children! And they are only in chasms!
DISCLAIMER: Not tested and little though put into it... so use at own risk.