Owie: Trust me, I'm quite upset that people are slaughtering my babies... They will learn soon... heh heh heh heh heh....
If you want something marginally impossible to kill, here's my living god template:
[OBJECT:CREATURE]
[CREATURE:LIVING_DIETY]
[NAME:living god:living gods:living god]
[TILE:'G'][COLOR:7:0:1]
[GLOWTILE:"G"][GLOWCOLOR:7:0:1]
[MEGABEAST][INTELLIGENT][AMPHIBIOUS]
[GENPOWER:5][STOUT][TRAPAVOID][VIEWRANGE:100]
[SPECNAME:FEMALE:living goddess:living goddesses:living goddess]
[FANCIFUL]
[CANOPENDOORS]
[PREFSTRING:enthralling provisions]
[PREFSTRING:immortality]
[PREFSTRING:invincibility]
[PREFSTRING:godhood]
[PREFSTRING:ascended nature]
[BODY:HUMANOID:2EYES:2EARS:NOSE:2LUNGS:HEART:GUTS:ORGANS:HUMANOID_JOINTS:THROAT:NECK:SPINE:BRAIN:5FINGERS:5TOES:MOUTH]
[NOPAIN][EXTRAVISION][NOBLEED][NOSTUN][NONAUSEA]
[NOSTUCKINS][NOEXERT][FIREIMMUNE_SUPER]
[FAT:50]
[BUILDINGDESTROYER:1]
[DAMBLOCK:1000]
[HEATDAM_POINT:13000]
[IGNITE_POINT:15000]
[BOILING_POINT:17000]
[BONE_BOILING_POINT:17000]
[BONE_COLDDAM_POINT:500]
[BONE_HEATDAM_POINT:13000]
[BONE_IGNITE_POINT:15000]
[BONE_MELTING_POINT:16000]
[LEATHER_BOILING_POINT:17000]
[LEATHER_COLDDAM_POINT:500]
[LEATHER_HEATDAM_POINT:13000]
[LEATHER_IGNITE_POINT:15000]
[LEATHER_MELTING_POINT:16000]
[MELTING_POINT:16000]
[LIGHT_GEN][LOCKPICKER][MAGMAVISION]
[COLDDAM_POINT:500]
[NOFEAR][FLIER]
[GRASSTRAMPLE:100]
[HOMEOTHERM:10100]
[LAYERING:1000]
[SIZE:500]
[ATTACK:MAIN:BYTOKEN:FINGER2:smite:smites:90:200:HEAT]
[ATTACK:SECOND:BYTYPE:GRASP:punch:punches:50:100:BLUDGEON][ATTACKFLAG_WITH]
[ATTACK:SECOND:BYTYPE:MOUTH:bite:bites:40:80:GORE][ATTACKFLAG_CANLATCH]
[EQUIPS]
[ALL_ACTIVE]
[MODVALUE:200]
[BIOME:ANY_LAND][CAN_LEARN][CAN_SPEAK][WEBIMMUNE]
[NO_DRINK][NO_EAT][NO_SLEEP][NOSMELLYROT][PARALYZEIMMUNE]
[SWIMS_LEARNED][SWIM_SPEED:2500]
[CANNOT_UNDEAD]
[PERSONALITY:SYMPATHY:0:50:100]
[PERSONALITY:ARTISTIC_INTEREST:0:50:100]
[PERSONALITY:INTELLECTUAL_CURIOSITY:0:50:100]
[PERSONALITY:MODESTY:0:50:100]
[PERSONALITY:ACTIVITY_LEVEL:0:50:100]
[PERSONALITY:SELF_EFFICACY:0:50:100]
[SPHERE:ART]
[SPHERE:NATURE]
[SPHERE:BOUNDARIES]
[SPHERE:COURAGE]
[SPHERE:EARTH]
[SPHERE:WATER]
[SPHERE:WEATHER]
[SPHERE:CHAOS]
[SPHERE:SUN]
It can still die though. It's hard (very, very hard), but possible. Keep in mind I haven't tested this in the newer versions though, so some of the tags might be outdated.