Las Vegas, Nevada - Charlie the kitten was left abandoned in a cardboard box outside an animal shelter in Las Vegas. There wasn't even a note! Would he ever be able to trust again?

He soon ended up with Nikki, a foster mom from the animal welfare organization Hearts Alive Village.

The kind woman knew that little Charlie would need around-the-clock care as he had to be bottle-fed.

"When he first came to me, he was a little over two weeks old. As he got older and started to scoot around more, he started to have more energy," the foster mother told Love Meow in an interview.

Dogs Dog tries to teach baby sister to play fetch – what happens next is a laugh riot!

However, she saw a potential behavioral problem on the horizon.

"Kittens that are single without their mates view their caretaker as their littermate. It’s important to redirect their behavior so they don’t get used to biting hands," Nikki explained.

Fortunately, she already had an idea of who could help her: a "permanent in-house foster cat" named Wallace!

"When Wallace met baby Charlie he was a hissy grump, so we're taking it slow," the woman admitted.

Fortunately, the cats got along better with each passing day.

Eventually, Wallace even started to groom his young ward.

Cats Cat has hysterical response to his mom's silly teasing in viral TikTok video

"My foster mama heart was exploding," Nikki gushed in another post.

"My big boy Wallace and my itty bitty Charlie!"

Nikki has since posted numerous photos and videos with her furry friends on her Instagram page, but soon it was time to say farewell.

That's because the kitten recently moved in with his new forever family.

While Wallace and Charlie will surely miss one another, the little guy will have a kitty sister to play with in his new home.