Imaginary friends aren't as fictitious as parents would like to believe, at least not in the world of Supernatural.

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The CW series will take on the figments of childhood fantasy when Sammy's (Jared Padalecki) old imaginary friend bursts into reality for "Just My Imagination."

Set to air as episode 8, the upcoming episode will introduce viewers to Sully, according to Variety. This long forgotten piece of Winchester history will appear in the form of Weird Loners' Nate Torrence.

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What's more, "Just My Imagination" will be directed by Supernatural alum Richard Speight Jr. The actor usually spends his time in front of the camera as the Trickster/archangel Gabriel, but Speight will jump into the director's chair as September comes to a close.

Supernatural's 11th season will open just seconds after the events of "Brother's Keeper." Facing down a tornado of Darkness, Sam and Dean (Jensen Ackles) will be holed up in the Impala as the series' newest big bad prepares to wreak havoc on an unsuspecting world.

Find out more when Supernatural returns to The CW on Oct. 7 at 9 p.m. ET. Click the video below to see a preview for the series' premiere, "Out of the Darkness, Into the Fire."