Killed by Mary Winchester

Beings killed by Mary Winchester.

Monsters

 * Countless unnamed monsters - Killed by Mary over the course of her hunting career.

Rugaru

 * Three unnamed Rugaru - Brains melted with the Rugaru Killing Gun.

Vampires

 * Vampire Nest Leader - Decapitated during the Raid on the British Men of Letters compound.
 * Two unnamed vampires - Decapitated during the Raid on the British Men of Letters compound.
 * Vampire nest in Lancaster, Missouri - All decapitated on a hunt.
 * Dozens of unnamed vampires in America - Killed with Arthur Ketch during Project V.

Werewolves

 * An unnamed werewolf - Decapitated with a shotgun blast of silver buckshot in 1980.
 * Unnamed pack of werewolves - Aided Max and Alicia Banes in killing on a hunt.

Hunters

 * Rick - Throat slit on the orders of the British Men of Letters while brainwashed.
 * Lester - Ripped apart on the orders of the British Men of Letters while brainwashed.
 * Multiple unnamed hunters - Killed on the orders of the British Men of Letters while brainwashed.

British Men of Letters

 * Ms. Watt - Stabbed through the back with an angel blade to save her son.
 * Arthur Ketch - Shot in the arm to stop him from killing Dean then executed with a shot to the head.