Watching This Rare Animal Befriend A 2-Legged Dog Is Beyond Sweet

It might be an unlikely friendship, but it's possibly the cutest.

Roo is a two-legged chihuahua who has no idea he's different from most dogs.

He runs, plays and, according to his owner, is one of the happiest dogs she's ever seen. 

Here's his best friend Penny, a rare silkie chicken. Penny was rescued from a testing facility.

She's soft and fluffy because, like all silkies, she was born without barbs, the thin branches that extend off of a feather's main shaft and help create its shape. 

The two unique animals love playing and cuddling together.

Their owner is a receptionist at an animal hospital. She brings Penny and Roo to work with her every day.

They both get their fill of attention by interacting with the customers who can't seem to get over their cuteness. 

In fact, it was a customer who generously offered to pay for Roo's custom-made wheelchair.

He has so much fun running around in it that he tires himself out and sometimes takes a quick nap in it. 

But there's one thing Roo loves even more than his wheelchair — his best friend, Penny.

Adopting and rescuing an animal can be just as rewarding for you as it is for them. 

Watch Roo and Penny in action in the video below by NatGeoWild.

Share Roo and Penny's story and put a smile on someone's face.