Actually the effects are fully and completely quantified, by the RAWs that someone was nice enough to extract form a savegame.
Here they are:
interaction_layer
[OBJECT:INTERACTION]
[INTERACTION:DISTURBANCE_1]
[GENERATED]
[I_SOURCE:DISTURBANCE]
[I_TARGET:A:CORPSE]
[IT_LOCATION:CONTEXT_ITEM]
[IT_FORBIDDEN:NOT_LIVING]
[IT_REQUIRES:FIT_FOR_RESURRECTION]
[IT_REQUIRES:CAN_SPEAK]
[IT_CANNOT_HAVE_SYNDROME_CLASS:WERECURSE]
[IT_CANNOT_HAVE_SYNDROME_CLASS:VAMPCURSE]
[IT_CANNOT_HAVE_SYNDROME_CLASS:DISTURBANCE_CURSE]
[I_EFFECT:RESURRECT]
[IE_TARGET:A]
[IE_IMMEDIATE]
[SYNDROME]
[SYN_CLASS:DISTURBANCE_CURSE]
[CE_DISPLAY_TILE:TILE:165:6:0:1:START:0]
[CE_DISPLAY_NAME:NAME:mummy:mummies:mummified:START:0]
[CE_PHYS_ATT_CHANGE:STRENGTH:300:1000:TOUGHNESS:300:1000:START:0]
[CE_ADD_TAG:NO_AGING:NOT_LIVING:OPPOSED_TO_LIFE:STERILE:EXTRAVISION:NOEXERT:NOPAIN:NOBREATHE:NOSTUN:NONAUSEA:NO_DIZZINESS:NO_FEVERS:NOEMOTION:PARALYZEIMMUNE:NOFEAR:NO_EAT:NO_DRINK:NO_SLEEP:NO_PHYS_ATT_GAIN:NO_PHYS_ATT_RUST:NOTHOUGHT:NO_THOUGHT_CENTER_FOR_MOVEMENT:NO_CONNECTIONS_FOR_MOVEMENT:START:0]
[CE_REMOVE_TAG:HAS_BLOOD:TRANCES:LIKES_FIGHTING:MISCHIEVOUS:START:0]
[CE_CAN_DO_INTERACTION:START:0]
[CDI:ADV_NAME:Curse]
[CDI:INTERACTION:DISTURBANCE_CURSE_1]
[CDI:TARGET:A:LINE_OF_SIGHT:DISTURBER_ONLY]
[CDI:TARGET_RANGE:A:25]
[CDI:USAGE_HINT:MAJOR_CURSE]
[CDI:VERBAL]
[CDI:VERBAL_SPEECH:curse.txt]
[CDI:TARGET_VERB:feel horrible:looks horrible]
[CDI:MAX_TARGET_NUMBER:A:1]
[CDI:WAIT_PERIOD:20]
[CE_CAN_DO_INTERACTION:START:0]
[CDI:ADV_NAME:Animate corpse]
[CDI:INTERACTION:DISTURBANCE_ANIMATE_1]
[CDI:TARGET:A:LINE_OF_SIGHT]
[CDI:TARGET_RANGE:A:25]
[CDI:VERB:gesture:gestures:NA]
[CDI:TARGET_VERB:shudder and begin to move:shudders and begins to move]
[CDI:WAIT_PERIOD:10]
interaction_layer
[OBJECT:INTERACTION]
[INTERACTION:DISTURBANCE_CURSE_1]
[GENERATED]
[I_TARGET:A:CREATURE]
[IT_LOCATION:CONTEXT_CREATURE]
[IT_CANNOT_TARGET_IF_ALREADY_AFFECTED]
[IT_MANUAL_INPUT:victim]
[I_EFFECT:ADD_SYNDROME]
[IE_TARGET:A]
[IE_IMMEDIATE]
[SYNDROME]
[CE_SKILL_ROLL_ADJUST:PERC:0:PERC_ON:20:START:0]
Highlighted is the curse's effects. It adjusts your skill rolls. In fact, 20% of all skill rolls you make will have a 0% success rate. It's like rolling a d20 in DnD that has a 1 on four of it's faces. You've got a 20% chance of a critical failure on any combat moves you make, and your opponents hold a die with four '20's on it, giving them a 20% chance of a critical success on any rolls they make against you.
What happened to you, WellBredMutt, is probably that you rolled a 1 on your attack, the mummy got a free counterstrike. You also rolled a 1 to defend against that counterstrike, making it a "critical hit", pulverizing some important body function that drastically reduced your speed, or caused you to instantly pass out from pain. Then, his turn came up several times before yours did, and he used his time to reduce you to a pile of bloody goo.
Moral of the story is;
stay the fuck away form mummies if you want to live.