That’s Delirium of the Endless on Enrico’s other shoulder.

Enrico (singing): Ah, ah, ah, ah, stayin’ alive, stayin’ alive!

Bet I can still do all of its Pray Pray Revolution steps…

Shoulder devil: That’s right! You’re king of the world! Judgments for everyone!

Enrico: Stayin’ aliiiive…

Shoulder devil: …hey, what happened to the angel?

Shoulder Delirium: He got lost in my domain, so I’m filling in.