Proper Dave

Proper Dave was a human who lived in the 51st century.

He was an explorer along with Strackman Lux, Other Dave, River Song and others, and served as the expedition's pilot. He was killed by the Vashta Nerada, although his consciousness survived for a brief time after as a Data Ghost.

Afterward, Vashta Nerada animated his skeleton and he became the Suit Creature, which continued to utter Dave's final words "Hey, who turned out the lights?" as a data ghost, which had fallen into an infinite loop. (DW: Silence in the Library / Forest of the Dead)