diff --git a/include/mondata.h b/include/mondata.h
index f565d9da1..b12d6e382 100644
--- a/include/mondata.h
+++ b/include/mondata.h
@@ -1,4 +1,4 @@
-/* NetHack 3.7	mondata.h	$NHDT-Date: 1606473485 2020/11/27 10:38:05 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.45 $ */
+/* NetHack 3.7	mondata.h	$NHDT-Date: 1703845738 2023/12/29 10:28:58 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.63 $ */
 /* Copyright (c) 1989 Mike Threepoint                             */
 /* NetHack may be freely redistributed.  See license for details. */
 
@@ -161,6 +161,8 @@
 #define is_rider(ptr)                                      \
     ((ptr) == &mons[PM_DEATH] || (ptr) == &mons[PM_FAMINE] \
      || (ptr) == &mons[PM_PESTILENCE])
+/* note: placeholder monsters are used for corposes of zombies and mummies;
+   PM_DWARF and PM_GNOME are normal monsters, not placeholders */
 #define is_placeholder(ptr)                             \
     ((ptr) == &mons[PM_ORC] || (ptr) == &mons[PM_GIANT] \
      || (ptr) == &mons[PM_ELF] || (ptr) == &mons[PM_HUMAN])
diff --git a/include/monsters.h b/include/monsters.h
index 14ee32dd6..a34c662c8 100644
--- a/include/monsters.h
+++ b/include/monsters.h
@@ -1,4 +1,4 @@
-/* NetHack 3.7	monsters.h	$NHDT-Date: 1700725870 2023/11/23 07:51:10 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.113 $ */
+/* NetHack 3.7	monsters.h	$NHDT-Date: 1703845746 2023/12/29 10:29:06 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.117 $ */
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /*-Copyright (c) Michael Allison, 2006. */
 /* NetHack may be freely redistributed.  See license for details. */
@@ -417,12 +417,13 @@
           NO_ATTK),
         SIZ(500, 200, MS_HUMANOID, MZ_SMALL), 0, 0, M1_HUMANOID | M1_OMNIVORE,
         M2_COLLECT, M3_INFRAVISIBLE | M3_INFRAVISION, 2, CLR_GREEN, HOBBIT),
+    /* unlike plain human|elf|orc, plain "dwarf" is an ordinary monster */
     MON("dwarf", S_HUMANOID, LVL(2, 6, 10, 10, 4), (G_GENO | 3),
         A(ATTK(AT_WEAP, AD_PHYS, 1, 8), NO_ATTK, NO_ATTK, NO_ATTK, NO_ATTK,
           NO_ATTK),
         SIZ(900, 300, MS_HUMANOID, MZ_HUMAN), 0, 0,
         M1_TUNNEL | M1_NEEDPICK | M1_HUMANOID | M1_OMNIVORE,
-        M2_NOPOLY | M2_DWARF | M2_STRONG | M2_GREEDY | M2_JEWELS | M2_COLLECT,
+        M2_DWARF | M2_STRONG | M2_GREEDY | M2_JEWELS | M2_COLLECT,
         M3_INFRAVISIBLE | M3_INFRAVISION, 4, CLR_RED, DWARF),
     MON("bugbear", S_HUMANOID, LVL(3, 9, 5, 0, -6), (G_GENO | 1),
         A(ATTK(AT_WEAP, AD_PHYS, 2, 4),
@@ -630,10 +631,9 @@
         SIZ(1000, 200, MS_ORC, MZ_HUMAN), 0, 0, M1_HUMANOID | M1_OMNIVORE,
         M2_ORC | M2_STRONG | M2_COLLECT, M3_INFRAVISIBLE | M3_INFRAVISION,
         3, CLR_BROWN, HOBGOBLIN),
-    /* plain "orc" for zombie corpses only; not created at random;
-     * orcs (but not goblins and hobgoblins) are granted poison resistance;
-     * however, their corpses don't confer it
-     */
+    /* Plain "orc" for zombie and mummy corpses only; not created at random.
+     * Orcs (but not goblins and hobgoblins) are granted poison resistance;
+     * however, their corpses don't confer it. */
     MON("orc", S_ORC, LVL(1, 9, 10, 0, -3), (G_GENO | G_NOGEN | G_LGROUP),
         A(ATTK(AT_WEAP, AD_PHYS, 1, 8),
           NO_ATTK, NO_ATTK, NO_ATTK, NO_ATTK, NO_ATTK),
@@ -1417,12 +1417,13 @@
         M2_HOSTILE | M2_NEUTER, 0, 5, CLR_MAGENTA, VIOLET_FUNGUS),
     /*
      * Gnomes
+     *  Unlike plain human|elf|orc, plain "gnome" is an ordinary monster.
      */
     MON("gnome", S_GNOME, LVL(1, 6, 10, 4, 0), (G_GENO | G_SGROUP | 1),
         A(ATTK(AT_WEAP, AD_PHYS, 1, 6), NO_ATTK, NO_ATTK, NO_ATTK, NO_ATTK,
           NO_ATTK),
         SIZ(650, 100, MS_ORC, MZ_SMALL), 0, 0, M1_HUMANOID | M1_OMNIVORE,
-        M2_NOPOLY | M2_GNOME | M2_COLLECT, M3_INFRAVISIBLE | M3_INFRAVISION,
+        M2_GNOME | M2_COLLECT, M3_INFRAVISIBLE | M3_INFRAVISION,
         3, CLR_BROWN, GNOME),
     MON3("gnome lord", "gnome lady", "gnome leader",
         S_GNOME, LVL(3, 8, 10, 4, 0), (G_GENO | 2),
@@ -2205,14 +2206,15 @@
     /*
      * humans, including elves and were-critters;
      *  the '@' class does not obey rule #2.
+     *  Plain "human" is a placeholder, not a normal monster.
      */
     MON("human", S_HUMAN, LVL(0, 12, 10, 0, 0), G_NOGEN, /* for corpses */
         A(ATTK(AT_WEAP, AD_PHYS, 1, 6),
           NO_ATTK, NO_ATTK, NO_ATTK, NO_ATTK, NO_ATTK),
         SIZ(WT_HUMAN, 400, MS_HUMANOID, MZ_HUMAN), 0, 0,
         M1_HUMANOID | M1_OMNIVORE,
-        M2_NOPOLY | M2_HUMAN | M2_STRONG | M2_COLLECT, M3_INFRAVISIBLE,
-        2, HI_DOMESTIC, HUMAN),
+        M2_NOPOLY | M2_HUMAN | M2_STRONG | M2_COLLECT,
+        M3_INFRAVISIBLE, 2, HI_DOMESTIC, HUMAN),
     MON("wererat", S_HUMAN, LVL(2, 12, 10, 10, -7), (1),
         A(ATTK(AT_WEAP, AD_PHYS, 2, 4),
           NO_ATTK, NO_ATTK, NO_ATTK, NO_ATTK, NO_ATTK),
@@ -2234,6 +2236,7 @@
         M1_HUMANOID | M1_POIS | M1_REGEN | M1_OMNIVORE,
         M2_NOPOLY | M2_WERE | M2_HOSTILE | M2_HUMAN | M2_COLLECT,
         M3_INFRAVISIBLE, 6, CLR_ORANGE, HUMAN_WEREWOLF),
+    /* plain "elf" is a placeholder, not a normal monster */
     MON("elf", S_HUMAN, LVL(0, 12, 10, 2, -3), G_NOGEN, /* for corpses */
         A(ATTK(AT_WEAP, AD_PHYS, 1, 8),
           NO_ATTK, NO_ATTK, NO_ATTK, NO_ATTK, NO_ATTK),
diff --git a/src/polyself.c b/src/polyself.c
index 807e5ef8c..c5f7b077a 100644
--- a/src/polyself.c
+++ b/src/polyself.c
@@ -1,4 +1,4 @@
-/* NetHack 3.7	polyself.c	$NHDT-Date: 1702274031 2023/12/11 05:53:51 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.204 $ */
+/* NetHack 3.7	polyself.c	$NHDT-Date: 1703845752 2023/12/29 10:29:12 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.207 $ */
 /*      Copyright (C) 1987, 1988, 1989 by Ken Arromdee */
 /* NetHack may be freely redistributed.  See license for details. */
 
@@ -502,6 +502,7 @@ polyself(int psflags)
     if (controllable_poly || forcecontrol) {
         buf[0] = '\0';
         tryct = 5;
+
         do {
             mntmp = NON_PM;
             getlin("Become what kind of monster? [type the name]", buf);
@@ -528,7 +529,28 @@ polyself(int psflags)
                     mntmp = (draconian && class == S_DRAGON)
                             ? armor_to_dragon(uarm->otyp)
                             : mkclass_poly(class);
+
+            /* placeholder monsters are for corpses and all flagged
+               M2_NOPOLY but they are reasonable polymorph targets;
+               pick a suitable substitute (which might be geno'd) */
+            } else if (is_placeholder(&mons[mntmp])
+                       /* when your own race, fall to !polyok() case */
+                       && !your_race(&mons[mntmp])
+                       /* same for generic human, even if hero isn't human */
+                       && mntmp != PM_HUMAN) {
+                /* far less general than mkclass() */
+                if (mntmp == PM_ORC)
+                    mntmp = rn2(3) ? PM_HILL_ORC : PM_MORDOR_ORC;
+                else if (mntmp == PM_ELF)
+                    mntmp = rn2(3) ? PM_GREEN_ELF : PM_GREY_ELF;
+                else if (mntmp == PM_GIANT)
+                    mntmp = rn2(3) ? PM_STONE_GIANT : PM_HILL_GIANT;
+                /* note: PM_DWARF and PM_GNOME are ordinary monsters and
+                   no longer flagged no-poly so have no need for placeholder
+                   handling; PM_HUMAN is a placeholder without a suitable
+                   substitute so gets handled differently below */
             }
+
             if (mntmp < LOW_PM) {
                 if (!class)
                     pline("I've never heard of such monsters.");
@@ -581,6 +603,7 @@ polyself(int psflags)
             } else
                 break;
         } while (--tryct > 0);
+
         if (!tryct)
             pline1(thats_enough_tries);
         /* allow skin merging, even when polymorph is controlled */