diff --git a/public/audio/bgm/battle_legendary_eternatus_p1.mp3 b/public/audio/bgm/battle_legendary_eternatus_p1.mp3
new file mode 100644
index 00000000000..742a3a198c7
Binary files /dev/null and b/public/audio/bgm/battle_legendary_eternatus_p1.mp3 differ
diff --git a/public/audio/bgm/battle_legendary_eternatus_p2.mp3 b/public/audio/bgm/battle_legendary_eternatus_p2.mp3
new file mode 100644
index 00000000000..2015e735840
Binary files /dev/null and b/public/audio/bgm/battle_legendary_eternatus_p2.mp3 differ
diff --git a/src/battle-scene.ts b/src/battle-scene.ts
index 57ca66e0dc4..721b55020f9 100644
--- a/src/battle-scene.ts
+++ b/src/battle-scene.ts
@@ -2525,6 +2525,10 @@ export default class BattleScene extends SceneBase {
         return 10.344;
       case "battle_legendary_zac_zam": //SWSH Zacian & Zamazenta Battle
         return 11.424;
+      case "battle_legendary_eternatus_p1": //SWSH Eternatus Battle
+        return 11.102;
+      case "battle_legendary_eternatus_p2": //SWSH Eternamax Eternatus Battle
+        return 0.0;
       case "battle_legendary_glas_spec": //SWSH Glastrier & Spectrier Battle
         return 12.503;
       case "battle_legendary_calyrex": //SWSH Calyrex Battle
diff --git a/src/battle.ts b/src/battle.ts
index 878a539cecf..49f5c39e7dd 100644
--- a/src/battle.ts
+++ b/src/battle.ts
@@ -382,6 +382,11 @@ export default class Battle {
             case SpeciesId.ZACIAN:
             case SpeciesId.ZAMAZENTA:
               return "battle_legendary_zac_zam";
+            case SpeciesId.ETERNATUS:
+              if (pokemon.getFormKey() === "eternamax") {
+                return "battle_legendary_eternatus_p2";
+              }
+              return "battle_legendary_eternatus_p1";
             case SpeciesId.GLASTRIER:
             case SpeciesId.SPECTRIER:
               return "battle_legendary_glas_spec";