This should work...
Add this to the end of [CREATURE:HUMAN] in creature_standard.txt in
{DF directory}/raw/objects
[PREFSTRING:invulnerability]
[SPHERE:LONGEVITY]
[AMPHIBIOUS]
[LIKES_FIGHTING][TRANCES]
[EXTRAVISION][MAGMA_VISION]
[GENERAL_MATERIAL_FORCE_MULTIPLIER:1:1000]
[NO_CONNECTIONS_FOR_MOVEMENT][NO_THOUGHT_CENTER_FOR_MOVEMENT]
[NO_PHYS_ATT_RUST]
[NOBREATHE][NO_DRINK][NO_EAT][NO_SLEEP]
[NO_DIZZINESS][NO_FEVERS][NOEXERT][NONAUSEA][NOPAIN][NOFEAR]
[NOSTUN][NOEMOTION]
[NOT_BUTCHERABLE][NOMEAT][NOSMELLYROT][NOSTUCKINS]
[SWIMS_INNATE]
[CV_REMOVE_TAG:CREATURE_CLASS]
[CV_REMOVE_TAG:SWIMS_LEARNED]
[CV_REMOVE_TAG:MAXAGE]
[APPLY_CURRENT_CREATURE_VARIATION]
[PHYS_ATT_RANGE:ENDURANCE:5000:5000:5000:5000:5000:5000:5000]
[PHYS_ATT_RANGE:DISEASE_RESISTANCE:5000:5000:5000:5000:5000:5000:5000]
[PHYS_ATT_RANGE:TOUGHNESS:5000:5000:5000:5000:5000:5000:5000]
[PHYS_ATT_RANGE:RECUPERATION:5000:5000:5000:5000:5000:5000:5000]
[MENT_ATT_RANGE:WILLPOWER:5000:5000:5000:5000:5000:5000:5000]
[SKILL_LEARN_RATES:200:NONE:NONE:NONE]
[FIREIMMUNE_SUPER]
[SELECT_MATERIAL:ALL]
[MULTIPLY_VALUE:15]
[COLDDAM_POINT:NONE]
[HEATDAM_POINT:NONE]
[IGNITE_POINT:NONE]
[IF_EXISTS_SET_MELTING_POINT:NONE]
[IF_EXISTS_SET_BOILING_POINT:NONE]
[SPEC_HEAT:30000]
[SELECT_MATERIAL:BLOOD] Need to make sure blood and pus aren't solid at regular temperatures.
[PLUS_MATERIAL:PUS]
[MELTING_POINT:10000]
[SELECT_TISSUE:ALL]
[TL_HEALING_RATE:1]