Cursed magic whistle can teleport you to your pet

src/apply.c

@@ -498,6 +498,8 @@ use_magic_whistle(struct obj *obj)
         You("produce a %shigh-%s.", Underwater ? "very " : "",
             Deaf ? "frequency vibration" : "pitched humming noise");
         wake_nearby(TRUE);
+        if (!rn2(2))
+            tele_to_rnd_pet();
     } else {
         /* it's magic!  it works underwater too (at a higher pitch) */
         You(Deaf ? alt_whistle_str : whistle_str,

src/teleport.c

@@ -804,6 +804,28 @@ teleport_pet(struct monst *mtmp, boolean force_it)
     return TRUE;
 }
 
+/* teleport to random pet, if valid location next to it */
+void
+tele_to_rnd_pet(void)
+{
+    struct monst *mtmp, *pet = (struct monst *) 0;
+    int cnt = 0;
+
+    for (mtmp = fmon; mtmp; mtmp = mtmp->nmon)
+        if (!DEADMONSTER(mtmp) && mtmp->mtame && !mon_offmap(mtmp)) {
+            cnt++;
+            if (!rn2(cnt))
+                pet = mtmp;
+        }
+    if (pet && !m_next2u(pet)) {
+        coordxy tx = pet->mx + rn2(3) - 1,
+                ty = pet->my + rn2(3) - 1;
+
+        if (isok(tx, ty) && teleok(tx, ty, FALSE))
+            teleds(tx, ty, TELEDS_TELEPORT);
+    }
+}
+
 /* teleport the hero via some method other than scroll of teleport */
 void
 tele(void)