Katy Perry recently appeared on the “Tonight Show” with Jimmy Fallon. The Grammy nominee's new song "Swish Swish" from the album "Witness" is said to be her answer to Taylor Swift's "Bad Blood."

Perry and Swift's famous feud allegedly started when Perry dated Swift's ex John Mayer. Swift and Mayer had a brief relationship in 2010, and two years after the split, Mayer dated Perry. However, things may have gotten more intense when three of Perry's "California Dreams" world tour dancers got picked up for Swift's 2012 world tour for her "Red" Album.

One of the three dancers, Lockhart Brownlie, said that at the time of Swift's tour, Perry's camp reached out to see if Brownlie and the two other dancers (Scott Myrick and Leah Adler) would be able to perform on her tour, and if they are, they would have to leave Swift's tour. All dancers agreed because, according to Brownlie, they are closer to Perry and they are not doing much dancing in Swift's tour anyway.

'Bad Blood' is about 'straight-up enemies'

In 2014, Taylor Swift said during an interview with Rolling Stone that her song "Bad Blood" is about her conflict about a popular music artist and that she and that person are "straight-up enemies." Many people automatically assumed that that person is no other than Katy Perry.

Swift made it clear that their feud is not over a guy.

Taylor Swift added that Perry basically sabotaged an entire tour. The day after the interview, Perry posted a cryptic tweet saying, "Watch out for the Regina George in sheep's clothing." This further fueled rumors.

Swift's ex Calvin Harris referenced about her rift between Perry as well.

Swift's team revealed that she actually collaborated in doing Rihanna's "This Is What You Came For," but the revelation was done in a manner that made Harris look like he is the bad guy. Harris confirmed that Swift contributed backing vocals to the song, but did not want to make a big deal out of it, so she used a pseudonym.

Harris famously said on Twitter that he knows Swift needs someone new to bury "like Katy," but added that he is not that guy.

Is 'Swish Swish' Perry's answer to 'Bad Blood?'

Now back to the present time, Perry said during her interview with Fallon that her new song "Swish Swish" is an anthem for people who are being held down or bullied. The song, which talks about getting over haters, is a collaboration with Nicki Minaj. The lyrics dissed someone who is "'bout cute as an old coupon expired."

Swift's close friends have come to her defense. Actress Ruby Rose took to Twitter to defend her pal, while music video director and Swift's longtime friend Joseph Kahn said: "If you're gonna do a diss track, at least put a decent hook on it." Katy Perry still has not specified if the song meant anyone in particular.