Ok. I think I've got it all fixed up (or at least the error log is blank and the game doesn't crash on them anymore)
[CREATURE:FLAME BEHEMOTH]
[DESCRIPTION:A truly titanic mammal. These creatures are unfortunately common.]
[NAME:fire behemoth:fire behemoths:fire behemoth]
[CASTE_NAME:fire behemoth:fire behemoth:fire behemoths]
[CHILD:10][GENERAL_CHILD_NAME:fire behemoth calf: fire behemoth calves]
[CREATURE_TILE:'!'][COLOR:7:0:0]
[PETVALUE:500000]
[PET]
[MOUNT]
[TRAINABLE]
[LARGE_ROAMING]
[BIOME:ANY_LAND]
[FREQUENCY:5]
[CAN_DO_INTERACTION:MATERIAL_EMISSION]
[CDI:ADV_NAME:Breath fire]
[CDI:USAGE_HINT:ATTACK]
[CDI:BP_REQUIRED:BY_CATEGORY:MOUTH]
[CDI:FLOW:DRAGONFIRE]
[CDI:TARGET:C:LINE_OF_SIGHT]
[CDI:TARGET_RANGE:C:15]
[CDI:MAX_TARGET_NUMBER:C:1]
[CDI:WAIT_PERIOD:50]
[FIREIMMUNE_SUPER][FLIER]
[MEANDERER][NATURAL]
[PREFSTRING:sheer enormity]
[BUILDINGDESTROYER:2]
[TRAPAVOID]
[NOPAIN][NOFEAR][NOEXERT][NONAUSEA][NO_DIZZINESS][NO_FEVERS]
[PRONE_TO_RAGE:1]
[LIKESFIGHTING]
[MEGABEAST][DIFFICULTY:10]
[USE_MATERIAL_TEMPLATE:MAGMA_CONTAGION:CREATURE_EXTRACT_TEMPLATE]
[STATE_COLOR:ALL:RED]
[STATE_NAME:ALL_SOLID:Frozen magma contagion]
[STATE_ADJ:ALL_SOLID:Frozen magma contagion]
[STATE_NAME:LIQUID:Liquid magma contagion]
[STATE_ADJ:LIQUID:Liquid magma contagion]
[STATE_NAME:GAS:Gaseous magma contagion]
[STATE_ADJ:GAS:Gaseous magma contagion]
[SYNDROME]
[SYN_NAME:Magma contagion]
[SYN_IMMUNE_CREATURE:FLAME BEHEMOTH:ALL]
[SYN_INHALED]
[CE_PAIN:SEV:10000:PROB:100:START:1:PEAK:15:END:15000]
[CE_UNCONSCIOUSNESS:SEV:10000:PROB:100:START:500:PEAK:15:END:15000]
[CE_FEVER:SEV:10000:PROB:100:START:10000:PEAK:11000:END:15000]
[CAN_DO_INTERACTION:MATERIAL_EMISSION]
[CDI:ADV_NAME:Breath magma contagion]
[CDI:USAGE_HINT:ATTACK]
[CDI:BP_REQUIRED:BY_CATEGORY:MOUTH]
[CDI:MATERIAL:LOCAL_CREATURE_MAT:MAGMA_CONTAGION:TRAILING_VAPOR_FLOW]
[CDI:TARGET:C:LINE_OF_SIGHT]
[CDI:TARGET_RANGE:C:15]
[CDI:MAX_TARGET_NUMBER:C:1]
[CDI:WAIT_PERIOD:50]
[NATURAL_SKILL:BITE:20]
[NATURAL_SKILL:GRASP_STRIKE:20]
[NATURAL_SKILL:RANGED_COMBAT:20]
[NATURAL_SKILL:MELEE_COMBAT:20]
[NATURAL_SKILL:DODGING:20]
[NATURAL_SKILL:SITUATIONAL_AWARENESS:20]
[ATTACK_TRIGGER:200:10000000:1000000]
[BODY:QUADRUPED:TAIL:2EYES:2EARS:TRUNK:2LUNGS:HEART:GUTS:ORGANS:THROAT:NECK:SPINE:BRAIN:SKULL:MOUTH:TONGUE:2TUSKS:GENERIC_TEETH:RIBCAGE]
[BODY_DETAIL_PLAN:STANDARD_MATERIALS]
[USE_MATERIAL_TEMPLATE:IVORY:TOOTH_TEMPLATE]
[STATE_NAME:ALL_SOLID:ivory]
[STATE_ADJ:ALL_SOLID:ivory]
[SELECT_MATERIAL:SKIN]
[MAT_FIXED_TEMP:60000]
[SELECT_MATERIAL:ALL]
[HEATDAM_POINT:NONE]
[IGNITE_POINT:NONE]
[SELECT_MATERIAL:BONE]
[USE_TISSUE_TEMPLATE:INORGANIC_ADAMANTINE]
[SELECT_MATERIAL:TUSK]
[USE_TISSUE_TEMPLATE:INORGANIC_ADAMANTINE]
[SELECT_MATERIAL:MUSCLE]
[SOLID_DENSITY:8250]
[BODY_DETAIL_PLAN:STANDARD_TISSUES]
[USE_TISSUE_TEMPLATE:IVORY:IVORY_TEMPLATE]
[BODY_DETAIL_PLAN:VERTEBRATE_TISSUE_LAYERS:SKIN:FAT:MUSCLE:BONE:CARTILAGE]
[SELECT_TISSUE_LAYER:HEART:BY_CATEGORY:HEART]
[PLUS_TISSUE_LAYER:SKIN: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]
[USE_MATERIAL_TEMPLATE:BLOOD:BLOOD_TEMPLATE]
[BLOOD:INORGANIC:OBSIDIAN:LIQUID]
[HAS_NERVES]
[BODY_SIZE:0:0:70000000]
[BODY_SIZE:2:0:140000000]
[BODY_SIZE:5:0:280000000]
[BODY_APPEARANCE_MODIFIER:LENGTH:90:95:98:100:102:105:110]
[BODY_APPEARANCE_MODIFIER:HEIGHT:90:95:98:100:102:105:110]
[BODY_APPEARANCE_MODIFIER:BROADNESS:90:95:98:100:102:105:110]
[ATTACK:KICK:BODYPART:BY_CATEGORY:FOOT_FRONT]
[ATTACK_SKILL:STANCE_STRIKE]
[ATTACK_VERB:kick:kicks]
[ATTACK_CONTACT_PERC:100]
[ATTACK_PRIORITY:MAIN]
[ATTACK_FLAG_WITH]
[ATTACK:GORE:BODYPART:BY_CATEGORY:TUSK]
[ATTACK_SKILL:BITE]
[ATTACK_VERB:gore:gores]
[ATTACK_PENETRATION_PERC:5]
[ATTACK_PRIORITY:MAIN]
[ATTACK_FLAG_WITH]
[DIURNAL]
[HOMEOTHERM:10066]
[SWIMS_INNATE][SWIM_SPEED:2500]
[LAIR:SIMPLE_BURROW:100]
[CASTE:FEMALE]
[FEMALE]
[CASTE:MALE]
[MALE]
[SELECT_CASTE:ALL]
[SET_TL_GROUP:BY_CATEGORY:ALL:SKIN]
[TL_COLOR_MODIFIER:GRAY:1]
[TLCM_NOUN:skin:SINGULAR]
[SET_TL_GROUP:BY_CATEGORY:EYE:EYE]
[TL_COLOR_MODIFIER:IRIS_EYE_BROWN:1:IRIS_EYE_GOLD:1:IRIS_EYE_YELLOW:1]
[TLCM_NOUN:eyes:PLURAL]
[SELECT_MATERIAL:ALL]
[MULTIPLY_VALUE:5]
Basically here is what I did:
1)You had a few typos in some of your tokens. The only noticeable one that seems like it might happen to you later is that DF uses the american spelling for "color" instead of the british one.
2)You had a few weird line breaks, noticeably in the middle of your body token, this mean only half of the body was being processed.
3)Some of your SELECT_MATERIAL things were above [BODY_DETAIL_PLAN:STANDARD_MATERIALS], meaning you were trying to select something that didn't exist yet.
4)You were defining the magma contamination material after the interaction, which meant the interaction was trying to use a material that didn't exist yet.
5)You forgot [BODY_DETAIL_PLAN:STANDARD_TISSUES]. I believe this is what was causing the crash.
6)You were lacking the tissue and materials for your tusks. I went ahead and named them ivory since that seemed more fitting and is what most tusked creatures use.
7)Lastly I combined/fixed your STATE_COLOR tokens and the states for some of your STATE_NAME/ADJ tokens.
8)I removed your MAXAGE token. It was too long for the game to handle (possibly causing a crash) and a creature that lives that long is practically immortal, so I just gave them the elven version of immortality (immune to old age).