With a shaved head and bulging biceps former Jonas Brothers singer Nick looks almost unrecognisable in the trailer for Direct-TV’s new series ‘Kingdom’. In the 10 part series, Nick stars as an aspiring MMA fighter trying to put his family's issues behind him as he trains for the Octagon. Alongside him is Frank Grillo, who plays Nick's former champion fighter father.

Nick JonasWho's have thought Nick Jonas would play an MMA fighter?

For the role, Nick gained around 15 pounds of muscle, transforming his body into that of a professional fighter. He told E! News, "I really wanted to look like an animal who internalizes a lot, but when he's in the cage and he's fighting that's when you see this kind of animalistic mentality that he has.”

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But Nick's also admitted his brothers found his new look slightly amusing, "They were calling me the Hulk and they were poking fun at me a little bit." he admitted. Nick has since dropped about seven to 10 pounds of the muscle he gained for the role saying, "The bulky muscle guy was probably good for a month or two, but I feel better where I'm at now".

Starring as Nick's father Alvey Kulina is Captain America: The Winter Soldier's Frank Grillo. Kulina is a retired MMA champion who currently works as a trainer out of his gym in Venice, California.

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'Parenthood's' Jonathan Tuckeralso appears as Nick's older delinquent brother whose behaviour threatens the family legacy. While Friday Night Lights' Matt Lauria can also be seen making a surprising turn as a MMA fighter recently released on parole.

Nick JonasNick bulked up his physique for the role, gaining 15 pounds of muscle

'Kingdom' premieres on DIRECTV's Audience network on Oct. 8 at 9 p.m, but in the meantime you can watch the trailer here.