Katy Perry mourns the death of her beloved pet cat, Kitty Purry

Losing a pet is never easy. Katy Perry is grieving over the death of the cat she's had for 15 years, which she affectionally named Kitty Purry.

The "Roar" singer mourned her beloved pet on Sunday and shared how the two first met: "Kitty Purry crawled through my then-boyfriend’s window 15 years ago, fully pregnant and seeking shelter."

The 35-year-old also included cute anecdotes of some of their past adventures, writing, "Two litters and many moons later, this street cat became a lovable mascot to many."

The singer included a collage of throwback photos of her snuggling Kitty, a medium-haired tabby with white markings on her chest and paws. She also included a heartbreaking photo of her FaceTiming with Kitty during her last moments.

"Sadly, Kitty completed her 9th life last night," Perry said. "I hope she rests in salmon fillets and tuna tartare way up in catnip heaven."

Despite saying goodbye to her loved sidekick, the "American Idol" judge will always cherish the memories the two shared. "Kitty, thanks for the cuddles and companionship along the way," she sweetly concluded before giving a shout-out to her brother, David Hudson, and Gareth Walters "for being great co-parents."

Walters also paid tribute to the late Kitty on Sunday, revealing a little more about the mischievous cat. "She had character and heart like no other animal I knew," he mourned. "I’m already missing the simple pleasures of her jumping into my lap, her constant purring, and her frequent disobedience to any rule I attempted to make for her."

Fans and friends, like Kris Jenner and Jeremy Scott, were quick to send Perry their sincere condolences.