diff --git a/data/json/monsters/zed_misc.json b/data/json/monsters/zed_misc.json
index a0683d946fcee..ea306a379dbbf 100644
--- a/data/json/monsters/zed_misc.json
+++ b/data/json/monsters/zed_misc.json
@@ -507,6 +507,7 @@
     "death_drops": "mon_zombie_hulk_death_drops",
     "regenerates": 15,
     "flags": [
+      "ALL_SEEING",
       "SEES",
       "HEARS",
       "GOODHEARING",
diff --git a/doc/JSON_FLAGS.md b/doc/JSON_FLAGS.md
index 7756eb3a845b6..00172e42f799f 100644
--- a/doc/JSON_FLAGS.md
+++ b/doc/JSON_FLAGS.md
@@ -990,6 +990,7 @@ Other monster flags.
 - ```ACIDPROOF``` Immune to acid.
 - ```ACIDTRAIL``` Leaves a trail of acid.
 - ```ACID_BLOOD``` Makes monster bleed acid. Does not automatically dissolve in a pool of acid on death.
+- ```ALL_SEEING``` Can see every creature within its vision (highest of day/night vision counts) on the same Z-level.
 - ```ALWAYS_VISIBLE``` This monster can always be seen regardless of line of sight or light level.
 - ```ANIMAL``` Is an _animal_ for purposes of the `Animal Empathy` trait.
 - ```AQUATIC``` Confined to water.
diff --git a/src/creature.cpp b/src/creature.cpp
index f6f6d7657ab5d..12d5442c95d34 100644
--- a/src/creature.cpp
+++ b/src/creature.cpp
@@ -352,6 +352,11 @@ bool Creature::sees( const Creature &critter ) const
     const Character *ch = critter.as_character();
     const int wanted_range = rl_dist( pos(), critter.pos() );
 
+    if( this->has_flag( MF_ALL_SEEING ) ) {
+        const monster *m = this->as_monster();
+        return wanted_range < std::max( m->type->vision_day, m->type->vision_night );
+    }
+
     // Can always see adjacent monsters on the same level.
     // We also bypass lighting for vertically adjacent monsters, but still check for floors.
     if( wanted_range <= 1 && ( posz() == critter.posz() || here.sees( pos(), critter.pos(), 1 ) ) ) {
diff --git a/src/monstergenerator.cpp b/src/monstergenerator.cpp
index 29a9142abde94..48e03ace47eff 100644
--- a/src/monstergenerator.cpp
+++ b/src/monstergenerator.cpp
@@ -199,7 +199,8 @@ std::string enum_to_string<m_flag>( m_flag data )
         case MF_ATTACK_LOWER: return "ATTACK_LOWER";
         case MF_DEADLY_VIRUS: return "DEADLY_VIRUS";
         case MF_ALWAYS_VISIBLE: return "ALWAYS_VISIBLE";
-        case MF_ALWAYS_SEES_YOU: return "ALWAYS_SEES_YOU";    
+        case MF_ALWAYS_SEES_YOU: return "ALWAYS_SEES_YOU";
+        case MF_ALL_SEEING: return "ALL_SEEING";
         // *INDENT-ON*
         case m_flag::MF_MAX:
             break;
diff --git a/src/mtype.h b/src/mtype.h
index 96038e0785720..2697342e97247 100644
--- a/src/mtype.h
+++ b/src/mtype.h
@@ -173,6 +173,7 @@ enum m_flag : int {
     MF_DEADLY_VIRUS,        // This monster can inflict the zombie_virus effect
     MF_ALWAYS_VISIBLE,      // This monster can always be seen regardless of los or light or anything
     MF_ALWAYS_SEES_YOU,     // This monster always knows where the avatar is
+    MF_ALL_SEEING,          // This monster can see everything within its vision range regardless of light or obstacles
     MF_MAX                  // Sets the length of the flags - obviously must be LAST
 };