King Nocturne

The King Nocturne was a conceptual being. The lord of the Nocturnes, whose weaker brethren the Doctor had faced long before the King itself, it was eventually destroyed by Sutekh in a fit of rage.

Biology
Like its brethren, the King Nocturne was a conceptual being made of living sound — tiny "quantum vibrations". Its true form was that of a monstrous worm-like creature which towered over humans. It had multiple legs, eyes and mandibles and its body was a red colour with a pale outline. (COMIC: The Jazz Monster)

Powers and abilities
The King Nocturne, like any conceptual being, was according to the Tenth Doctor, "very versatile". It could manipulate sound for various and creative purposes.

On Earth, the King Nocturne could possess people and link them together to form an incubation field that allowed it to fully materialise physically in N-Space. The people it possessed could fire electrical arcs that incinerated their targets. It could also form a shield of solid sound around an entire building to prevent anyone from escaping. (COMIC: The Jazz Monster)

Biography
The King Nocturne was attracted to early-20th century New Orleans, on Earth, where jazz was just starting to bud. It began possessing people with musical talent such as Paradisa and Roscoe Ruskin, with whom Cindy Wu had fallen in love. It then sealed the building off with a force field and linked the people it was possessing together, creating an "incubation field" that would allow it to materialise on Earth. However, the Tenth Doctor and Gabby once again thwarted this attempt but only partially: Paradisa and Roscoe, still possessed, managed to escape and everyone inside the building, except for the Doctor, Gabby and Cindy, had been killed by the Nocturne. It resurfaced two days later in Chicago, where Roscoe was supposed to have a song recorded. The Nocturne planned to plant itself in the song that would then be sold across the world in order to possess more people. The Doctor and Gabby had managed to travel there the day before using the TARDIS and successfully repelled the Nocturne. This freed Paradisa from its control but it killed Roscoe. (COMIC: The Jazz Monster)

The King Nocturn was eventually released from the Void, where the Doctor had sent it, alongside many other gods from beyond the universe, by Sutekh. Though the Doctor managed to contain them inside a suspension field, the Nocturne broke free and prepared to kill Cindy. Before it could, Sutekh stopped it and obliterated it completely, jealous of other beings trying to put themselves outside his control. (COMIC: Old Girl)