Muskego, Wisconsin - Shortly after a cat named Callie gave birth, her kittens died. The distraught mama became so aggressive that she was placed on a euthanasia list. Luckily, one woman took a chance and rescued her. Now, this cat's maternal instincts are melting thousands of hearts.

Julia Stuller, who lives in Muskego, Wisconsin, took a chance on this aggressive mama cat in August 2021.

She saved Callie from being put to sleep, but the cat was still feisty and unwilling to trust her new owners.

All that changed when Stuller became pregnant. Suddenly, Callie became very affectionate and demanded cuddles and pets.

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In July 2022, Stuller's daughter Emma was born, and Callie was ready for her new role as the baby's protector!

"She was no longer aggressive, and she became such a sweet cat. It was like she thought our daughter was a kitten, so she'd lick her, comfort her, and come to her cries like a mother would," Stuller told Newsweek.

From day one, Callie and Emma became the best of buds. Stuller says that Callie loves to be by Emma's side.

The cat even sneaks into the nursery to cuddle with Emma!

"We don't let them sleep together for safety reasons, but Callie does help put her to sleep every night," Stuller said.

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What's more, Stuller's TikTok videos of this unlikely duo have the internet swooning over the cuteness. Users love how this formerly aggressive cat has warmed up to this little human.

"It's funny because we were worried at first that Callie wouldn't like the new baby and would be aggressive, but it turned out to be the opposite," the proud mother said.