With a little modification of the dwarf's creature file, they now no longer bleed, sleep, feel pain, breathe, or drown. They now can swim in water (though they will cancel any jobs and repeatedly fall into the same body of water, which can get
VERY irritating) and they can swim in, and not burn up in magma, get happy thoughts from killing, and have new personality traits.
However, they can also breathe fire on foes (which has blasted the legs of many goblins) and have a venomous falcon punch and bite, permanently paralysing their foe after a short period of time.
If you want to change your dwarves into a super-race of domination, the code is below. Just don't get seiged by other dwarves, or you'll be in deep trouble. Otherwise, you can best most armed foes, but don't send unarmed dwarves into a small crowd of goblin spearmen, they'll probably only polish off one goblin before being slain themselves.
[CREATURE:DWARF]
put this in creature_standard.txt in raw/objects
[NAME:dwarf:dwarves:dwarven]
[TILE:1][COLOR:3:0:0]
[GENPOWER:3]
[BUTCHERABLE_NONSTANDARD]
[INTELLIGENT]
[RECKLESS]
[TRANCES]
[BENIGN]
[EXTRACT:giant cave spider venom:7:0:0]
[EXTRACT_VALUE:100]
[EXTRACT_PARALYZE][EXTRACT_PERMANENT][NATURAL][PET_EXOTIC]
[EXTRACT_ANTIDOTE:giant cave spider antivenin:7:0:0:10]
[CANOPENDOORS]
[LIKES_FIGHTING][FIREIMMUNE_SUPER][MAGMA_VISION][NOBREATHE][NOBLEED]
[WEBIMMUNE][AMBUSHPREDATOR][PARALYZEIMMUNE][FIREBREATH]
[EXTRAVISION][NOSTUN][NOEXERT][NOFEAR][AMPHIBIOUS][NO_SLEEP]
[PREFSTRING:beards]
[BODY:HUMANOID:2EYES:2EARS:NOSE:2LUNGS:HEART:GUTS:ORGANS:HUMANOID_JOINTS:THROAT:NECK:SPINE:BRAIN:5FINGERS:5TOES:MOUTH]
[STOUT][PARALYZEIMMUNE]
[NOBLEED][NOFEAR][NONAUSEA][NOEXERT][NOPAIN]
[MAXAGE:150:170]
[ATTACK:MAIN:BYTYPE:GRASP:punch:punches:5:10:BURN][ATTACKFLAG_WITH][SPECIALATTACK_INJECT_EXTRACT:50:100]
[ATTACK:SECOND:BYTYPE:MOUTH:munch:munches:5:25:GORE][ATTACKFLAG_CANLATCH][SPECIALATTACK_INJECT_EXTRACT:100:250]
[CHILD:2][BABY:1][MULTIPLE_LITTER_RARE]
[DAMBLOCK:1]
[FAT:3]
[SIZE:6]
[EQUIPS]
[CAVE_ADAPT]
[HEATDAM_POINT:13000]
[IGNITE_POINT:13500]
[LEATHER_HEATDAM_POINT:13000]
[LEATHER_IGNITE_POINT:13500]
[BONE_HEATDAM_POINT:14000]
[DIURNAL]
[CRAFTSMAN_NAME:craftsdwarf:craftsdwarves]
[FISHERMAN_NAME:fisherdwarf:fisherdwarves]
[HAMMERMAN_NAME:hammerdwarf:hammerdwarves]
[SPEARMAN_NAME:speardwarf:speardwarves]
[CROSSBOWMAN_NAME:marksdwarf:marksdwarves]
[AXEMAN_NAME:axedwarf:axedwarves]
[SWORDSMAN_NAME:swordsdwarf:swordsdwarves]
[MACEMAN_NAME:macedwarf:macedwarves]
[PIKEMAN_NAME:pikedwarf:pikedwarves]
[BOWMAN_NAME:bowdwarf:bowdwarves]
[SPEECH:dwarf.txt]
[STANDARD_FLESH]
[HOMEOTHERM:10125]
[LAYERING:50]
[ALCOHOL_DEPENDENT]
[SWIMS_LEARNED][SWIM_SPEED:2500]
[PERSONALITY:IMMODERATION:0:55:100]
[PERSONALITY:VULNERABILITY:0:45:100]
[PERSONALITY:STRAIGHTFORWARDNESS:0:55:100]
[PERSONALITY:EXCITEMENT_SEEKING:0:60:100]
[PERSONALITY:CHEERFULNESS:0:40:90]
[PERSONALITY:ALTRUISM:0:25:50]
[PERSONALITY:MODESTY:0:40:90]
[PERSONALITY:SYMPATHY:0:25:50]
Do keep a backup of your original creature_standard.txt in the raw/objects folder, otherwise bad things will happen.
All of the object definitions in the raw/objects folder are open to modification, so you can shape the game to your liking.
Also, screenshots o' plenty.