|Actor|| Misha Collins|
|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 is black and viscous with the ability to shift 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 the only being able to revive angels or demons slumbering in the Empty.
Its power is so great that when it stormed Heaven, the Entity easily bypassed all of Heaven's defenses, killing at least one angel in the process. It was able to blast open all of Heaven's gates, even the ones permanently closed years before by Metatron, and could possess angels, essentially using them as its vessels.
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 itself, 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.
After reuniting with the Winchesters, Castiel mentions that he returned after annoying the Entity to the point that it sent him back to Earth.
With Jack's death, the Entity lays a claim on Jack's soul, despite him being half-human. It storms the Gates of Heaven, bypassing all defenses as well as opening all gates, even the ones permanently closed by Metatron years earlier. When Jack realizes there is something wrong in his Heaven, he ventures outside of it to find out what has happened, but is quickly met by the Entity, who barrels towards Jack as a flood of black viscous goo, causing Jack to retreat into the Heaven of his mother, Kelly Kline.
Castiel arrives in Heaven in the aftermath of the Entity's initial siege, finding the seemingly dead angels Zuriel and Dumah. Dumah awakens soon after Castiel's arrival, explaining to Castiel how everything went black when she came into contact with the Entity. Needing to find Jack, Castiel and Dumah go to Jack's personal Heaven. They are met there by Naomi, who explains to Castiel what happened, and how the small number of angels in Heaven couldn't stop the Entity. She suggests they give it what it wants -- Jack -- rather than risk Heaven failing and allowing all the souls in Heaven to fall. The Entity soon appears to take over Naomi's body; she warns Castiel and Dumah to run before being taken over.
In Kelly Kline's personal Heaven, Castiel and Dumah locate Jack and his mother in a house. After telling Jack they've found a way to bring him back, Castiel tells him the Entity has invaded Heaven in its pursuit of Jack and they need to leave. Dumah reveals herself to be the Entity, which tells Jack it is taking him to the Empty. It asks Castiel if Jack and Kelly's fear hurts him, as that's what it wants to do -- hurt Castiel. Before the Entity can leave with Jack, Castiel offers himself up in Jack's stead, agreeing to go with the Entity back to the Empty. The Entity agrees, but tells Castiel it won't be right away. It wants to wait for the day Castiel allows himself to be truly happy, and on that day, the Entity will come and drag him back into the nothing. Castiel accepts and the Entity releases its hold over Dumah and disappears in a nearby vent, presumably returning to the Empty.
- The Cosmic Entity's 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.
- The concept of the Empty is reminiscent of Sheol, which the Hebrew Bible describes as a place of stillness and darkness, cut off from life and God, where both the righteous and the wicked go upon death. The concept of the Cosmic Entity is also reminiscent of the inhabitants of Sheol: Rephaim, or shades, which are described as entities without personality or strength that provide healing and blessings to the lives of the living.
- Misha Collins received a question regarding his accent in this film at the 2017 Honolulu Convention. Although he claims it came from nowhere, it's evident he knows the "Mid-Atlantic" connection as he calls it an accent from an "oil rig in the Atlantic." The "Mid-Atlantic" accent's name comes from being a cross between England and New England, hence halfway through the Atlantic ocean. It is an artificial accent used in old Hollywood movies.
- In 14.08 Byzantium, the entity is also referred to as "the shadow" by Naomi, as well as "the Empty" by Castiel during their conversation. Though the two discussed the actual Empty, Castiel specifically called the entity the Empty as well and it agreed with him.