Giants wear stomping boots can sometimes stomp medium sized monsters

Obviously this is really powerful (basically a vorpal blade on boots) so it's only 1 in 40 chance on each attack.

src/uhitm.c

@@ -492,17 +492,18 @@ register struct monst *mtmp;
         }
     }
 
-    if (uarmf && uarmf->otyp == STOMPING_BOOTS && !Levitation 
-        && mtmp->data->msize <= MZ_SMALL) {
-        if (verysmall(mtmp->data) || !rn2(4)) {
+
+    if (uarmf && uarmf->otyp == STOMPING_BOOTS && !Levitation) {
+        if ((mtmp->data->msize <= MZ_SMALL && (verysmall(mtmp->data) || !rn2(4))) 
+            || (Race_if(PM_GIANT) && mtmp->data->msize == MZ_MEDIUM && !rn2(40))) {
             You("stomp on %s!", mon_nam(mtmp));
             xkilled(mtmp, XKILL_GIVEMSG);
             wake_nearby();
             makeknown(uarmf->otyp);
             return TRUE;
         }
     }
-
+    
     /* possibly set in attack_checks;
        examined in known_hitum, called via hitum or hmonas below */
     override_confirmation = FALSE;