diff --git a/include/monsters.h b/include/monsters.h
index b1bb58edb..45b01d3ae 100644
--- a/include/monsters.h
+++ b/include/monsters.h
@@ -1,4 +1,4 @@
-/* NetHack 3.7	monsters.h	$NHDT-Date: 1703845746 2023/12/29 10:29:06 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.117 $ */
+/* NetHack 3.7	monsters.h	$NHDT-Date: 1705092146 2024/01/12 20:42:26 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.119 $ */
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /*-Copyright (c) Michael Allison, 2006. */
 /* NetHack may be freely redistributed.  See license for details. */
@@ -3351,6 +3351,12 @@
                                        | M2_STRONG | M2_COLLECT | M2_MAGIC,
         M3_INFRAVISIBLE, 8, HI_DOMESTIC, APPRENTICE),
 
+    /*
+     * mons_init() in monst.c adds a terminator here, mons[NUMMONS].
+     * It is part of the mons[] array without introducing another type
+     * of monster.
+     */
+
 #if defined(MONS_ENUM) || defined(DUMP_ENUMS)
 #undef MON
 #undef MON3
diff --git a/src/monst.c b/src/monst.c
index 2b85c22c3..c3b03f396 100644
--- a/src/monst.c
+++ b/src/monst.c
@@ -1,4 +1,4 @@
-/* NetHack 3.7	monst.c	$NHDT-Date: 1682205027 2023/04/22 23:10:27 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.97 $ */
+/* NetHack 3.7	monst.c	$NHDT-Date: 1705092160 2024/01/12 20:42:40 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.100 $ */
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /*-Copyright (c) Michael Allison, 2006. */
 /* NetHack may be freely redistributed.  See license for details. */
@@ -8,63 +8,60 @@
 #include "wintype.h"
 #include "sym.h"
 
-#ifdef C
-#undef C
-#endif
 #include "color.h"
-#define C(color) color
 
-#define NO_ATTK    \
-    {              \
-        0, 0, 0, 0 \
-    }
+#define NO_ATTK { 0, 0, 0, 0 }
 
+/* monster type with single name */
 #define MON(nam, sym, lvl, gen, atk, siz, mr1, mr2, \
             flg1, flg2, flg3, d, col, bn)           \
     {                                                                       \
         { (const char *) 0, (const char *) 0, nam },                        \
         PM_##bn,                                                            \
-        sym, lvl, gen, atk, siz, mr1, mr2, flg1, flg2, flg3, d, C(col)      \
+        sym, lvl, gen, atk, siz, mr1, mr2, flg1, flg2, flg3, d, col         \
     }
 
+/* monster type with distinct male, female, neuter names */
 #define MON3(namm, namf, namn, sym, lvl, gen, atk, siz, mr1, mr2, \
              flg1, flg2, flg3, d, col, bn)                        \
     {                                                                       \
         { namm, namf, namn },                                               \
         PM_##bn,                                                            \
-        sym, lvl, gen, atk, siz, mr1, mr2, flg1, flg2, flg3, d, C(col)      \
+        sym, lvl, gen, atk, siz, mr1, mr2, flg1, flg2, flg3, d, col         \
     }
+
 /* LVL() and SIZ() collect several fields to cut down on number of args
- * for MON()
+ * for MON()/MON3().
  */
 #define LVL(lvl, mov, ac, mr, aln) lvl, mov, ac, mr, aln
 #define SIZ(wt, nut, snd, siz) wt, nut, snd, siz
 /* ATTK() and A() are to avoid braces and commas within args to MON() */
-#define ATTK(at, ad, n, d) \
-    {                      \
-        at, ad, n, d       \
-    }
-#define A(a1, a2, a3, a4, a5, a6) \
-    {                             \
-        a1, a2, a3, a4, a5, a6    \
-    }
+#define ATTK(at, ad, n, d) { at, ad, n, d }
+#define A(a1, a2, a3, a4, a5, a6) { a1, a2, a3, a4, a5, a6 }
 
 struct permonst mons_init[NUMMONS + 1] = {
 #include "monsters.h"
     /*
-     * array terminator
+     * Array terminator, added to the end of the entries in monsters.h.
+     *
+     * mons[NUMMONS] used to be all zero except "" instead of Null for
+     * the name field.  Then the index field was added and the terminator
+     * uses NON_PM for that.  Now, a few monster flags also get set.
      */
 #undef MON
 #define MON(nam, sym, lvl, gen, atk, siz, mr1, mr2, \
             flg1, flg2, flg3, d, col, bn)           \
     {                                                                       \
         { (const char *) 0, (const char *) 0, nam },                        \
-        NON_PM,                                                            \
-        sym, lvl, gen, atk, siz, mr1, mr2, flg1, flg2, flg3, d, C(col)      \
+        NON_PM,                                                             \
+        sym, lvl, gen, atk, siz, mr1, mr2, flg1, flg2, flg3, d, col         \
     }
-    MON("", 0, LVL(0, 0, 0, 0, 0), (0),
+    MON("", 0, LVL(0, 0, 0, 0, 0),
+        G_NOGEN | G_NOCORPSE,
         A(NO_ATTK, NO_ATTK, NO_ATTK, NO_ATTK, NO_ATTK, NO_ATTK),
-        SIZ(0, 0, 0, 0), 0, 0, 0L, 0L, 0, 0, 0, 0),
+        SIZ(0, 0, 0, 0), 0, 0,
+        0L,  M2_NOPOLY, 0,
+        0, 0, 0),
 };
 
 #undef MON
@@ -86,8 +83,6 @@ const struct attack c_sa_no[NATTK] = SEDUCTION_ATTACKS_NO;
 
 /* for 'onefile' processing where end of this file isn't necessarily the
    end of the source code seen by the compiler */
-#undef C
-#define C(c) (0x1f & (c)) /* global.h */
 #undef NO_ATTK
 #undef LVL
 #undef SIZ