|Episode(s)||13.04 The Big Empty|
What do I want? I want you to shut up! I want -- hmm. Having you awake. It's like a gnat flew right up here. And it's trapped and it's buzzing... If you can't sleep, I can't sleep. Yeah? And I like sleep. I need sleep.
– Cosmic Entity, 13.04 The Big Empty
According to the entity, its true form is horrific enough that it can drive an angel insane from viewing it. The entity can appear in a black, viscous humanoid form before shifting its shape to appear as it wishes. In the case of meeting Castiel, it takes on the form of his vessel, Jimmy Novak. The Cosmic Entity also holds domain over the Empty, its will surpassing even God's, making it him the only being able to revive angels or demons slumbering in the Empty.
As Castiel begins exploring the Empty, the Cosmic Entity is awakened. As Castiel passes it by, the entity pulls itself out of the black nothingness and takes on a humanoid shape, covered in a black viscous liquid.
When Castiel feels its presence, the Cosmic Entity reveals himself, taking on the form of Castiel's vessel, Jimmy Novak, telling Castiel that its true form would drive him mad and cause him to claw his eyes out. The Entity goes on to explain what it is and at Castiel's insistence reveals they are in the Empty, the place where all angels and demons go when they die. It tells Castiel they are "sleeping an endless peaceful sleep," as was it, until Castiel woke up, which woke the entity up, drawing its ire. When Castiel explains that he doesn't know why he is awake, the Cosmic Entity begins torturing him, going into his mind to try and glean any information that could explain why Castiel has awoken.
The Cosmic Entity tells Castiel it wants to sleep and as long as Castiel is awake, it will remain awake. Castiel suggests the Entity send him back to Earth, but the Entity threatens to throw Castiel deeper into the Empty instead. When Castiel calls its bluff, the Entity begins mocking Castiel, telling him there is nothing for him on Earth and forcing Castiel to relive horrible memories.
As Castiel lays prone on the ground, the Entity begins stroking Castiel's head, telling him to save himself by going back to sleep. Castiel tries to stand up to the Entity, who begins violently kicking him, now demanding that he go back to sleep. Defiant, Castiel pulls himself to his feet, telling the Entity that he will stay awake until they both go insane. He demands the Entity release him or be forced to fight Castiel for all eternity.
Defeated, the Cosmic Entity acquiesces to Castiel's demands and resurrects him. Castiel later wakes up in a field, freed from the Empty.
- The Cosmic Entity's supposed horrific true visage, as well as his state of being in a deathlike sleep, bear some similarities with the Great Old Ones of H.P. Lovecraft's writings, specifically the ruler of the Outer Gods, Azathoth, also known as the "Blind Idiot God", who slumbers outside of creation and dreams of the Universe. The Entity's black viscous form also bears similarity to Magnum Innominandum, the Nameless Mist.