Rezh Baphix

Chorister Rezh Baffix was the last Chorister of Akhaten. Much like all Choristers, he was a servant of the Mummy. He sang the Long Song along with Merry Galel while in the pyramid. The unending song ended with him when the Mummy awoke.

When the Eleventh Doctor and Clara Oswald entered the pyramid to save him and Merry, he teleported from there to save himself. (TV: The Rings of Akhaten)