Phantom of the Bwahpera

"Phantom of the Bwahpera," titled "Phantom's Theme" in the museum's music list, is a song with lyrics in Mario + Rabbids Kingdom Battle. The title is a reference to the musical . This song is sung by the Phantom, and it was used in the game's second trailer. He sings the first verse at the beginning of his boss battle and the third verse at the beginning of his third phase. The second verse he sang, however, was unused for the second phase.

The song is sung opera style, and it is most notable for its lyrics, something mainly absent from other Super Mario games. In the song, Phantom tries to dissuade Mario and company from fighting him, and tells him that he is ready to "reign." As he does so, he repeatedly derides various aspects of the Super Mario franchise, such as making use of the Toads' catchphrase from Super Mario Bros., "Your Princess is in another castle.", Mario's physique and limited dialogue, the Spiny Shell from the Mario Kart series, and the Mushroom item. The song was composed by Grant Kirkhope, written by Ubisoft employee Cristina Nava, and sung by Augustin Chemelle, a French baritone opera singer.

Lyrics
Underlined lyrics are spoken and not sung.

Act 1: Bwah... Hum...ah-ehm Bwaaaah-Bwah-Bwah BwaaaaAAAAAAAAAAAH! Bwah Ahem-har...  Humph! You think yours is a real moustache? Who's done me a thousand wrongs Ever since Donkey Kong? Slithering down every pipe Despite his plumb-shaped body type! Who's gonna run in fear While screaming 'Mamma miaaaaaaaaaa'? Who leaves me gray and grim? Oh, what does Peach see in him? MARIO! With great joy in my heart Each time I watch Mario Kart! You're first and doing so well But here comes the Spiny Shell! (Ha ha ha!) And now you and your Rabbid friends Have finally met your ends! Just let me catch my breath Then I'll 'high C' you to death! 

Act 2 (unused): So that is all you've got, You didn't hurt me a lot! I'll help you to recap: Between you and me, There's a gap! Mario, you're such a bore... Your blows just make me snore! You haven't hurt me a single bit (Ha ha ha!) Prepare for my greatest HIT! 

Act 3: Who do you think you are? You should kneel, I’m the STAR! You are nothing but a parody I’ll find you a good role in a TRAGEDY. (Hahahaha!) “It’s-a me!” “Let’s-a go!” The only words you know! My art will touch your princess’s HEART And you will be pulled APAAAAART! You think you’ll win this tournament? I’ll send you to retirement! You’re so NOT worth the hassle! Your princess is in another castle! Mushrooms won’t end the pain... Time for the Phantom to start his reign!

Trivia

 * Earlier in the game's development, the team intended for the Phantom to change musical style in each phase; one phase would have an opera song, another a rap song, and the final one a metal song. However, this was scrapped due to the other styles not working very well.
 * The concept of the Phantom changing musical styles throughout his battle was eventually implemented in the Rayman in the Phantom Show DLC in Mario + Rabbids Sparks of Hope with him beginning with jazz, then switching to heavy metal, and finishing off with opera.