King Nocturne

The Nocturne was a conceptual being imprisonned inside another universe along with Sutehk and a number of other godlike beings who were a threat to the Doctor's universe. (COMIC: The jazz monster)

Biology
The Nocturne was a conceptual being made of living sound. 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 color with a pale outline. (COMIC: The jazz monster)

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

On Wupatki, the Nocturne hid itself as a virus inside songs broadcast from a radio station. The virus could infect the Shan'tee, another race of conceptual beings made of living sound. Once it took over their bodies, it deformed them and they gained a Grim Reaper-like appearance and became mindless killing machines. The virus quickly learned how to infect humans and could even adapt to different counterattacks. (COMIC: The singer, not the song)

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