diff --git a/crawl-ref/source/cloud.cc b/crawl-ref/source/cloud.cc
index d9ad0bfcf40..ac4d19756da 100644
--- a/crawl-ref/source/cloud.cc
+++ b/crawl-ref/source/cloud.cc
@@ -507,16 +507,6 @@ static void _handle_spectral_cloud(const cloud_struct& cloud)
                                100, RANDOM_MONSTER,
                                0);
 
-    if (basetype == RANDOM_MONSTER && one_chance_in(4))
-    {
-        do
-        {
-            basetype = pick_random_zombie();
-        }
-        while (mons_class_flag(basetype, M_NO_GEN_DERIVED)
-               || !monster_habitable_grid(basetype, grd(cloud.pos)));
-    }
-
     monster* agent = monster_by_mid(cloud.source);
     create_monster(mgen_data(MONS_SPECTRAL_THING,
                              (cloud.whose == KC_OTHER ?
diff --git a/crawl-ref/source/dungeon.cc b/crawl-ref/source/dungeon.cc
index 2d7c58326c1..4b7c0f27d5a 100644
--- a/crawl-ref/source/dungeon.cc
+++ b/crawl-ref/source/dungeon.cc
@@ -3533,11 +3533,31 @@ static void _place_aquatic_monsters()
                       false);
 }
 
+static vector<monster_type> _zombifiables()
+{
+    vector<monster_type> z;
+    for (monster_type mcls = MONS_0; mcls < NUM_MONSTERS; ++mcls)
+    {
+        if (mons_species(mcls) != mcls
+            || !mons_zombie_size(mcls)
+            || mons_is_unique(mcls)
+            || mons_class_holiness(mcls) != MH_NATURAL
+            || mons_class_flag(mcls, M_NO_GEN_DERIVED))
+        {
+            continue;
+        }
+
+        z.push_back(mcls);
+    }
+    return z;
+}
+
 // For Crypt, adds a bunch of skeletons and zombies that do not respect
 // absdepth (and thus tend to be varied and include several types that
 // would not otherwise spawn there).
 static void _place_assorted_zombies()
 {
+    static const vector<monster_type> zombifiable = _zombifiables();
     int num_zombies = random_range(6, 12, 3);
     for (int i = 0; i < num_zombies; ++i)
     {
@@ -3545,16 +3565,15 @@ static void _place_assorted_zombies()
         monster_type z_base;
         do
         {
-            z_base = pick_random_zombie();
+            z_base = zombifiable[random2(zombifiable.size())];
         }
-        while (mons_class_flag(z_base, M_NO_GEN_DERIVED)
-               || !(skel ? mons_skeleton(z_base) : mons_zombifiable(z_base)));
+        while (skel && !mons_skeleton(z_base));
 
         mgen_data mg;
         mg.cls = (skel ? MONS_SKELETON : MONS_ZOMBIE);
         mg.base_type = z_base;
-        mg.behaviour              = BEH_SLEEP;
-        mg.map_mask              |= MMT_NO_MONS;
+        mg.behaviour = BEH_SLEEP;
+        mg.map_mask |= MMT_NO_MONS;
         mg.preferred_grid_feature = DNGN_FLOOR;
 
         place_monster(mg);
diff --git a/crawl-ref/source/mon-place.cc b/crawl-ref/source/mon-place.cc
index efe64196905..2caccca5b46 100644
--- a/crawl-ref/source/mon-place.cc
+++ b/crawl-ref/source/mon-place.cc
@@ -1816,31 +1816,6 @@ static monster* _place_monster_aux(const mgen_data &mg, const monster *leader,
     return mon;
 }
 
-monster_type pick_random_zombie()
-{
-    static vector<monster_type> zombifiable;
-
-    if (zombifiable.empty())
-    {
-        for (monster_type mcls = MONS_0; mcls < NUM_MONSTERS; ++mcls)
-        {
-            if (mons_species(mcls) != mcls || mcls == MONS_PROGRAM_BUG)
-                continue;
-
-            if (!mons_zombie_size(mcls) || mons_is_unique(mcls))
-                continue;
-            if (mons_class_holiness(mcls) != MH_NATURAL)
-                continue;
-
-            zombifiable.push_back(mcls);
-        }
-
-        ASSERT(!zombifiable.empty());
-    }
-
-    return zombifiable[random2(zombifiable.size())];
-}
-
 // Check base monster class against zombie type and position if set.
 static bool _good_zombie(monster_type base, monster_type cs,
                          const coord_def& pos)
diff --git a/crawl-ref/source/mon-place.h b/crawl-ref/source/mon-place.h
index 56866eee156..dcfd6a3bdbf 100644
--- a/crawl-ref/source/mon-place.h
+++ b/crawl-ref/source/mon-place.h
@@ -49,8 +49,6 @@ const monster_type fixup_zombie_type(const monster_type cls,
  * *********************************************************************** */
 monster* place_monster(mgen_data mg, bool force_pos = false, bool dont_place = false);
 
-monster_type pick_random_zombie();
-
 /* ***********************************************************************
  * Returns a monster class type of a zombie for generation
  * on the player's current level.