Activator MOB_DAMAGE

MOB_DAMAGE is executing when player left-clicking or shooting mob. You can define mob type (name supported too) and item (in player's hand) for this activators

/react add MOB_DAMAGE <ActivatorId> type:<MobType> name:<MobName> [item:<Item>]

Example:

/react add MOB_DAMAGE SuperCowKill name:{&6Super Cow} type:COW item:{type:STICK}

Temporary placeholders provided by this activator

Placeholder	Description
%moblocation%	Location of mob
%mobtype%	Mob type. If you using Citizens plugins - NPC will have type "PLAYER"
%mobname%	Mob name. If mob has no custom name this placeholder will be equal to mob type
%mobdamager%	Player who hitting mob
%damage%	Damage the will deal to mob. You can modify this temporary variable using VAR_TEMP_SET action to change value of mob damage