Starters hold their Battle-gimmick items

src/battle_setup.c

@@ -984,14 +984,21 @@ void ChooseStarter(void)
 static void CB2_GiveStarter(void)
 {
     u16 starterMon;
+    u16 item;
     u8 evs[NUM_STATS]        = {0, 0, 0, 0, 0, 0};
     u8 ivs[NUM_STATS]        = {MAX_PER_STAT_IVS + 1, MAX_PER_STAT_IVS + 1, MAX_PER_STAT_IVS + 1,   // We pass "MAX_PER_STAT_IVS + 1" here to ensure that
                                 MAX_PER_STAT_IVS + 1, MAX_PER_STAT_IVS + 1, MAX_PER_STAT_IVS + 1};  // ScriptGiveMonParameterized won't touch the stats' IV.
     u16 moves[MAX_MON_MOVES] = {MOVE_NONE, MOVE_NONE, MOVE_NONE, MOVE_NONE};
 
     *GetVarPointer(VAR_STARTER_MON) = gSpecialVar_Result;
     starterMon = GetStarterPokemon(gSpecialVar_Result);
-    ScriptGiveMonParameterized(0, PARTY_SIZE, starterMon, 5, ITEM_NONE, ITEM_POKE_BALL, NUM_NATURES, 2, MON_GENDERLESS, evs, ivs, moves, FALSE, FALSE, NUMBER_OF_MON_TYPES);
+    if (gSpecialVar_Result == 0)      // Grookey
+        item = ITEM_GRASSIUM_Z;       // gimmicks are Terrain and type Z-Crystal
+    else if (gSpecialVar_Result == 1) // Litten
+        item = ITEM_INCINIUM_Z;       // gimmicks are stat changes and move Z-Crystal
+    else                              // Mudkip
+        item = ITEM_SWAMPERTITE;      // gimmicks are Mega Evolution and single type weakness
+    ScriptGiveMonParameterized(0, PARTY_SIZE, starterMon, 5, item, ITEM_POKE_BALL, NUM_NATURES, 2, MON_GENDERLESS, evs, ivs, moves, FALSE, FALSE, NUMBER_OF_MON_TYPES);
     ResetTasks();
     PlayBattleBGM();
     SetMainCallback2(CB2_StartFirstBattle);