This is a file from the game called UNDERTALE. The file is called mus_mettetonex.ogg. The MettetonEX fight only appears to the player in a pasifist or a true pasifist run. Genocide run will play a different song and the boss is named MettetonNEO. The players goal in the Metteton EX fight is to get 10,000 ratings. Once the player has achieved the goal then the fight will stop and there will be a random caller. The first caller is Napstablook. Then there are other random monsters. Once the fight ends Alphys will say he got there and then will be suprised to see metteton laying on the ground. He will say oh my god. The player then can move on. In the Genocide Run however the Metteton NEO fight the goal is to hit Metteton NEO once. This is not a acual BOSS battle as Metteton does not give any attacks. 

Mettaton Ex Song UNDERTALE

Josh Kernop