Scourge of the Galaxy

"Scourge of the Galaxy" was a phrase applied to various evils in passing, depending on what galaxy was being mentioned.

Frobisher claimed that the Whifferdill were the Scourge of the Galaxy. (COMIC: The Shape Shifter)

Geralk said the Cybermen used to be the Scourge of the Galaxy. (AUDIO: Return to Telos)

The Tenth Doctor later called Baltazar the Scourge of the Galaxy, (TV: The Infinite Quest) and applied the same title to the Macra in M87. (TV: Gridlock)