Surgeon (The End of the World)

The spayers are two people of unknown origin and race. They are covered with white suits that cover their faces so it is unknown. They look human but are not, seeing as Lady Cassandra O'Brien is the last human at thta time. They work for Cassandra by spraying her with water to keep her alive. They appeared to be just employees of hers, until she threatened the Doctor that he would be sprayed with acid by them. When Cassandra teleported away the sprayers came with her, but when the Doctor teleported her back, they stayed at the destination, where ever it was. This was a mistake for Cassandra, seeing she died of dried up skin when she called for them, but they didn't come.