The "Chained to the Rhythm" singer flawlessly channeled Snow White during Sunday night's Disney-themed American Idol, and brought along her tiny teacup poodle, Nugget, who was appropriately dressed as Minnie Mouse.
ET's Lauren Zima chatted with the pop star (and her pup) on the red carpet about Perry's costume of choice.
"Well, she is Nugget, and she is a big fan of Minnie Mouse," the 33-year-old Idol judge told ET. "I'm a massive fan of Disney. You know, when they asked me if I had anything to wear for the Disney episode, I was like, 'Actually, I've had something in my warehouse for about four years.'"
Perry confessed that the Snow White outfit for the live show was a repurposed Halloween costume that went unworn.
"I meant to wear this years ago for Halloween, and I was like, the universe always knows, so I pulled it out, popped on a wig, and voila!"
The pop star also spoke out about her strong reaction to discovering that her American Idol crush, Cade Foehner, was rumored to be dating fellow contestant Gabby Barrett.
"It's fine, to each their own," she shared. "You know, I'm happy for him, and he's probably happy for me. We don't talk to the contestants in between, so you know its up to them, their personal life."
The judge continued, joking that she'll have to just "get over it."
"I've heard that he's taken interest in another contestant, and that's just fine, I'm gonna get over it," she joked. "Snow White would never say what she's thinking right now, or else she wouldn't be a part of the Disney family."