The 'Firework' singer was the half-time performer at the world's biggest sporting event on Sunday, 1 February, so it's only natural she'd want to remember the occasion…
But rather than putting together a photo book or requesting a DVD of the blistering performance, she went one step further and had 'XLIX' – the Latin numerals for 49 - tattooed onto her finger.
Still dressed in her impressive stage make-up and costume, the singer headed for the nearest tattoo artist to have the Super Bowl XLIX memory inked onto a finger on her right hand.
She told fans: "I thought it would be appropriate to draw blood tonight."
Katy's performance at the massive event received huge applause as she stormed her way through a set list of favourites including 'Roar', 'Teenage Dream', 'I Kisssed a Girl' and 'California Gurls'.
She had support on stage from Lenny Kravitz, who gave 'I Kissed A Girl' a fabulously rock twist, and Missy Elliott, who performed a fab medley of her greatest hits.
Alongside the costume changes, special guests and pyrotechnics were stage props that included an enormous metal tiger, dancing sharks and a fireworks display.
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