WATCH: Instagram sensation Lil BUB dies at age 8

With more than 2.4 million Instagram followers, Lil BUB was one of the original online cat sensations. Sadly, the little feline that was diagnosed with a severe case of feline dwarfism has died.

Her owner Mike Bridavsky posted a heartfelt message to Instagram on Tuesday, notifying her fans of her passing: "On the morning of Sunday, December 1st 2019 we lost the purest, kindest and most magical living force on our planet. BUB was cheerful and full of love laying in our bed with us Saturday night, but unexpectedly passed away peacefully in her sleep."

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This is my first photo with BUB next our last photo together. On the morning of Sunday, December 1st 2019 we lost the purest, kindest and most magical living force on our planet. BUB was cheerful and full of love laying in our bed with us Saturday night, but unexpectedly passed away peacefully in her sleep.. I have always been fully transparent about BUB's health, and it was no secret that she was battling a persistent and aggressive bone infection. Even knowing this, we weren't expecting her to pass so soon or so abruptly without warning. I truly believe that she willingly made the decision to leave her failing body so that our family would not have to make that difficult decision ourselves. It is impossible to put into words the profound effect that BUB has had on my life, on the lives of thousands of homeless pets, and on the lives of those of you that have cared for her as if she were your own family. She taught me everything that I know about unconditional love, she brought my wife Stacy and I together, she's the reason we have our beautiful children Rosco and Lula, and she has been a constant source of warmth and love in our lives for the past 8 years. To say that our family is devastated would be an understatement. But most importantly, BUB has made a huge difference in the world of animal welfare, and in the lives of millions of people worldwide. She has literally saved thousands of lives (both pets and humans), she started the first national fund for special needs pets, she was the subject of groundbreaking genetic and biological research, she's helped raise over $700,000 for animals in need, and has spread a message of determination, positivity, and perseverance to people all over the world. And even though my heart is absolutely crushed by her graceful departure from planet Earth, I know that her sprit, magic, and overwhelming energy are still with us, reminding us every day to be better. Dearest BUB, I will never forget your generosity, your limitless supply of love, or your uncanny ability to bring so much magic and joy to the world. I am forever honored and humbled that you chose me as your caretaker. Please visit all of us in our dreams o

A post shared by Lil BUB(@iamlilbub) on Dec 2, 2019 at 9:25am PST

Shortly after after her death, Bridavsky posted a series of pictures of her.

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In loving memory of the most amazing cat on the planet, here is a collection of clips from some of my favorite BUB videos over the years. It is a four part series, so swipe right to see em all. GOOD JOB BUB. #lilbub

A post shared by Lil BUB(@iamlilbub) on Dec 3, 2019 at 2:59pm PST

Lil BUB found Instagram fame in 2012 when she appeared on the front page of Reddit. Bridavsky started a Tumblr page of her photos when he adopted her in 2011.

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Losing a pet is a difficult and complicated process, and only more so when your pet was loved by so many. While I was the one that cared for and took care of BUB, she was not MY cat - she was OUR cat. It's a tough time for sure, but in hindsight I can see that it really was her time to go, and she knew exactly what she was doing when she decided to go back to space the way that she did. It's going to take some time to get used to a world without her, but she left it a better place. I'm going to take a few days off from posting, but I promise to continue to share the many magical moments and memories from the past 8 years once our family has had some time to recover. BTW - there may be a memorial service in Bloomington soon. And if you see companies selling "RIP BUB" shirts, those aren't from us, they're just trying to make a quick buck. Due to overwhelming popular demand, we will be making some commemorative BUB merchandise in the coming weeks. If you'd like to stay up to date on the memorial service, new commemorative BUB stuff, and other developments, you can sign up for the newsletter at the link in BUB's bio (www.lilbub.com/newsletter) Thanks for all of your support. #bestjobbub #lilbub #scienceandmagic

A post shared by Lil BUB(@iamlilbub) on Dec 4, 2019 at 1:36pm PST