Supernatural's Demon Dean is on the loose, and hell's newest resident isn't thinking about anything except the moment in front of him.

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As far as Dean is concerned, halcyon days have finally come for the elder Winchester. From booze, to girls, to terrible karaoke, Dean will be letting his id rule the roost when season 10 premieres.

Unfortunately, that includes trying to embed an ax in Sammy's skull (see video below). Dean will spend the first two episodes trying to avoid his brother, but when they do come face-to-face, Dean will be a scary kind of "carefree."

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"There's nothing funny about this at all," Ackles said of Dean's new attitude, according to Spoiler TV. "He's so just kind of carefree and careless, [and] that I think is the scariest part about it to me, playing it."

Demon Dean's new outlook will be in stark contrast to his troubled mind in season 9.

"There was a lot riding on Dean's shoulders last season. It was torturous for him and it was a really, really tough year so what I wanted to do in contrast for Demon Dean was I wanted it to be Dean without any of that stuff," Ackles explained. "So he is essentially kind of the same guy, but he is a Dean without any care in the world and so much so that it's scary how little he cares about any-and-everybody. Even himself. Even the car."

Poor Impala. Let's hope Dean doesn't do any serious damage to his Baby.

Find out more when Supernatural returns to The CW on Oct. 7 at 9 p.m. ET.