use ability num instead of alt ability

src/field_specials.c

@@ -1433,7 +1433,7 @@ void PutZigzagoonInPlayerParty(void)
     u16 monData;
     CreateMon(&gPlayerParty[0], SPECIES_ZIGZAGOON, 7, 0x20, FALSE, 0, FALSE, 0);
     monData = TRUE;
-    SetMonData(&gPlayerParty[0], MON_DATA_ALT_ABILITY, &monData);
+    SetMonData(&gPlayerParty[0], MON_DATA_ABILITY_NUM, &monData);
     monData = MOVE_TACKLE;
     SetMonData(&gPlayerParty[0], MON_DATA_MOVE1, &monData);
     monData = MOVE_NONE;