Uh-oh, watch out, Taylor Swift. Katy Perry has some anger issues.

The 29-year old Perry told Harper's Bazaar that despite her upbeat and energetic personality, she can transform into a totally different person when she's mad. 

The singer goes on to explain what she's like on an "off day".

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"I can snap a little bit, be a little bitchy to the couple of people around me. Tamra, my assistant, is my closest punching bag. But she's strong and understands that I have a lot of pressure on me sometimes," she explained.

Perry added that aside from using her assistant as a human punching bag, she turns to cigarettes to calm her nerves when she's mad. She admits that it's a horrible habit, but that she needs to have a few puffs after downing a couple of drinks during her week off. She explained, however, that she doesn't "do black tar heroin."

Despite having gone through emotional turmoil and breakups, Perry has learned to cope with stress through therapy and meditation. She said she has learned to love herself first before anybody else.

But can Perry extend the love to her now-enemy, singer Taylor Swift?

In a cryptic, although fairly obvious, fight, the two singers have taken their disdain for each other publicly.

In an interview with Rolling Stone magazine, Swift admitted that her new angry song "Bad Blood" was about a fellow female singer, adding that whenever they saw each other during awards shows, she didn't really know if they were friends or not.

Swift said she was able to confirm later on that they weren't friends when the other stole her backup dancers while she was in the middle of her "Red" tour.

All signs pointed to Katy Perry as the object of her anger. Perry had taken away three of Swift's backup dancers while they were both on tour, in order to add them to her own show.

Tagskaty perry, taylor swift