Katy Perry is very assertive on her new catchy song Dark Horse, featuring rapper Juicy J.

"I knew you were, you were gonna come to me and here you are. But you better choose carefully cause I'm capable of anything, of anything and everything," she sings in the opening lyrics.

The Three 6 Mafia rapper also attests to Perry's words.

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"Be careful. Try not to lead her on. Shorty heart is on steroids cause her love is so strong," he raps. "You might fall in love when you need her. If you get the chance you better keep her."

Perry stated via Twitter that the song won't be her next single but it will appear on her upcoming album Prism.

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"Tonight a brand NEW color from PRISM #DARKHORSE will premiere on @iTunesMusic 12:01AM EDT/9:01PM PDT as part of the PRISM PREORDER! READY!?" she tweeted on Monday.

The album's lead single Roar shot to No. 1 on Billboard when it was released earlier in September and overthrew Robin Thicke's Blurred Lines from the top spot. The rest of the record, due out on Oct. 22, will also showcase a more mature side of Perry than her past albums.

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"It's the 28-year-old version of me. Last record, which was very fun, and kind of like a cartoon character. This record is a lot more stripped down," she recently told Elvis Duran And The Morning Show of New York City's Z-100. "It's the essential oils of me represented."

She also explained the meaning behind the album's unique title.

"Prism is what colors are. That's why I called [the album] Prism. For a minute I thought I was going to do a dark record, but then I let the light in, and that's what a Prism does."

Tags: Katy Perry