Spivak

Spivak was a demon that used to serve Crowley.

History
Spivak, ordered by Crowley, was among the demons that researched Lucifer's Cage, studying every warded molecule that keep the Lucifer in. He then added the same warding onto Nick, Lucifer's vessel, so that Crowley could control him.

After this Spivak and all other demons that studied the cage were killed by Crowley, in order to keep the wards a secret.

Apperance

 * Season 12
 * The British Invasion  (mentioned only)