Tested. Being flesh and bones, fireimmune won't save the tarrasque.
The heat eventually gets him.
[CREATURE:TARRASQUE]
[DESCRIPTION:A colossal creature, dwarfing even dragons. Immortal, Mighty and Invulnerable. It destroys entire civilizations in its rampage, then sleeps for a thousand years after feeding. There is only one Tarrasque in the known world, and woe to the one disturbing it.]
[NAME:Tarrasque:Tarrasque:Tarrasque]
[CASTE_NAME:Tarrasque:Tarrasque:Tarrasque]
[CREATURE_TILE:228][COLOR:6:0:0][EXTRAVISION]
[BIOME:ANY_LAND][CANNOT_UNDEAD][FANCIFUL]
[FREQUENCY:1][POP_RATIO:1:1][ARENA_RESTRICTED]
[SPHERE:CHAOS][SPHERE:DEATH][CURIOUSBEAST_EATER][CURIOUSBEAST_GUZZLER]
[NOFEAR][NOPAIN][BUILDINGDESTROYER:2][TRAPAVOID][VESPERTINE]
[LIKES_FIGHTING][PARALYZEIMMUNE][CLUSTER_NUMBER:1:1]
[GRASSTRAMPLE:100][WEBIMMUNE][BONECARN][NOEXERT][NO_DIZZINESS][NO_FEVERS]
[PREFSTRING:terrible majesty][LAIR:LABYRINTH:100][BIOME:ANY_LAND]
[MEGABEAST][NATURAL_SKILL:BITE:10][NATURAL_SKILL:GRASP_STRIKE:10]
[NATURAL_SKILL:STANCE_STRIKE:10][NATURAL_SKILL:MELEE_COMBAT:10]
[NATURAL_SKILL:DODGING:3][NATURAL_SKILL:SITUATIONAL_AWARENESS:10]
[ATTACK_TRIGGER:80:200000:1000000]
[BODY:QUADRUPED:TAIL:2HEAD_HORN:2EYES:NOSE:2LUNGS:HEART:GUTS:ORGANS:THROAT:NECK:SPINE:BRAIN:SKULL:3TOES_FQ:3TOES_RQ:MOUTH:GENERIC_TEETH_WITH_LARGE_EYE_TEETH:RIBCAGE]
[BODY_SIZE:0:0:500000]
[BODY_SIZE:1000:0:75000000]
[BODY_APPEARANCE_MODIFIER:LENGTH:100:110:125:150:175:200:250]
[BODY_APPEARANCE_MODIFIER:HEIGHT::100:110:125:150:175:200:250]
[BODY_APPEARANCE_MODIFIER:BROADNESS:100:110:125:150:175:200:250]
[PHYS_ATT_RANGE:STRENGTH:4000:4000:4000:4000:4000:4000:4000]
[RELSIZE:BY_CATEGORY:RHORN:450]
[RELSIZE:BY_CATEGORY:LHORN:450]
[BODY_DETAIL_PLAN:STANDARD_MATERIALS]
[REMOVE_MATERIAL:SKIN]
[REMOVE_MATERIAL:LEATHER]
[REMOVE_MATERIAL:HAIR]
[USE_MATERIAL_TEMPLATE:SCALE:METAL_TEMPLATE]
[STATE_NAME:ALL_SOLID:scales]
[STATE_ADJ:ALL_SOLID:scales]
[PLUS_MATERIAL:BONE]
[PLUS_MATERIAL:TOOTH]
[STATE_COLOR:ALL_SOLID:GOLD]
[DISPLAY_COLOR:6:7:1]
[IMPACT_YIELD:2500000]
[IMPACT_FRACTURE:3000000]
[IMPACT_ELASTICITY:2000]
[SHEAR_YIELD:1480000]
[SHEAR_FRACTURE:2390000]
[SHEAR_ELASTICITY:2000]
[SOLID_DENSITY:10000]
[SELECT_MATERIAL:MUSCLE]
[PLUS_MATERIAL:BRAIN]
[PLUS_MATERIAL:HEART]
[PLUS_MATERIAL:LUNG]
[IMPACT_YIELD:1620000]
[IMPACT_FRACTURE:1620000]
[IMPACT_ELASTICITY:60000]
[SHEAR_YIELD:780000]
[SHEAR_FRACTURE:1390000]
[SHEAR_ELASTICITY:2000]
[SOLID_DENSITY:60000]
[SELECT_MATERIAL:ALL]
[MULTIPLY_VALUE:50]
[BODY_DETAIL_PLAN:STANDARD_TISSUES]
[REMOVE_TISSUE:SKIN]
[REMOVE_TISSUE:HAIR]
[USE_TISSUE_TEMPLATE:HORN:HORN_TEMPLATE]
[TISSUE_MATERIAL:INORGANIC:ADAMANTINE]
[TISSUE_SHAPE:STRANDS]
[HEALING_RATE:50]
[USE_TISSUE_TEMPLATE:SCALE:SCALE_TEMPLATE]
[SELECT_TISSUE_LAYER:ALL]
[TL_HEALING_RATE:1]
[BODY_DETAIL_PLAN:VERTEBRATE_TISSUE_LAYERS:SCALE:FAT:MUSCLE:BONE:CARTILAGE]
[SELECT_TISSUE_LAYER:HEART:BY_CATEGORY:HEART]
[PLUS_TISSUE_LAYER:SCALE:BY_CATEGORY:THROAT]
[TL_MAJOR_ARTERIES]
[BODY_DETAIL_PLAN:STANDARD_HEAD_POSITIONS]
[BODY_DETAIL_PLAN:HUMANOID_RIBCAGE_POSITIONS]
[USE_MATERIAL_TEMPLATE:SINEW:SINEW_TEMPLATE]
[TENDONS:LOCAL_CREATURE_MAT:SINEW:200]
[LIGAMENTS:LOCAL_CREATURE_MAT:SINEW:200]
[HAS_NERVES]
[USE_MATERIAL_TEMPLATE:BLOOD:BLOOD_TEMPLATE]
[BLOOD:LOCAL_CREATURE_MAT:BLOOD:LIQUID]
[USE_MATERIAL_TEMPLATE:PUS:PUS_TEMPLATE]
[PUS:LOCAL_CREATURE_MAT:PUS:LIQUID]
[ATTACK:BITE:CHILD_BODYPART_GROUP:BY_CATEGORY:HEAD:BY_CATEGORY:TOOTH]
[ATTACK_SKILL:BITE]
[ATTACK_VERB:bite:bites]
[ATTACK_CONTACT_PERC:100]
[ATTACK_PENETRATION_PERC:100]
[ATTACK_FLAG_EDGE]
[ATTACK_PRIORITY:MAIN]
[ATTACK_FLAG_CANLATCH]
[ATTACK:GORE:BODYPART:BY_CATEGORY:HORN]
[ATTACK_SKILL:BITE]
[ATTACK_VERB:gore:gores]
[ATTACK_CONTACT_PERC:100]
[ATTACK_PRIORITY:MAIN]
[ATTACK_FLAG_WITH]
[SWIMS_INNATE][SWIM_SPEED:1000]
[HOMEOTHERM:10040]
[SET_TL_GROUP:BY_CATEGORY:ALL:SCALE]
[TL_COLOR_MODIFIER:GOLD:1]
[TLCM_NOUN:scales:PLURAL]
[SET_TL_GROUP:BY_CATEGORY:EYE:EYE]
[TL_COLOR_MODIFIER:BLACK:1]
[TLCM_NOUN:eyes:PLURAL]