Leo the pit bull with Katie Newhouser, UPS driver Leo always loved visiting Katie Newhouser when her truck rolled into the neighborhood. (Photo: Katie Newhouser/Facebook)

Leo the pit bull didn't have a lot of friends in his southern California condo complex. Because of Leo's massive size, neighbors were afraid of the friendly dog and asked his owner to muzzle him when he was outside his home.

But UPS delivery driver Katie Newhouser wasn't afraid of Leo; the pair had a special bond.

"He would hear my truck come into the condo complex and start barking and scratching at the door to come down to the truck," Newhouser tells Pup Journal. "He would love to come into the truck and go into the back to look around."

Newhouser was close to Leo's owner, Tina, and learned that Tina's son Cannon had brought him home as a tiny puppy. The dog was too young to eat so Tina had to bottle-feed the little guy; that's how the became so inseparable.

But after returning to her route after a vacation, Newhouser learned through a Facebook post that Tina had passed away. She immediately contacted Cannon and offered to foster Leo. She already had three other dogs of her own and didn't intend to keep him but we know how it happens — the dog already had a hold of her heart.

"The whole vibe in the house changed as soon as we brought him home. He is the biggest, most lovable dog that you will ever meet. He was instantly running around the yard with my dogs."

“He loves going for rides, he loves the water, he loves playing with his chew toys, he loves tormenting his two feline sisters, he loves laying in the sun, he has NO concept of personal space. He likes to be on us or right beside us! He is a character,” Newhouser tells People.

Of course when he moved in, there were a few adjustments. Leo was used to eating people food and now eats canine chow. As a compromise, Newhouser adds boiled chicken to all the dogs' meals, which makes the new dog even more popular with the pack.

Leo the pit bull relaxes with his new canine buddies Leo is now quite at home with his new canine buddies. (Photo: Katie Newhouser/Facebook)

Although Leo seems to enjoy his new home, he has occasional moments of sadness.

“Leo missed Tina when he first got here,” Newhouser tells Pup Journal. “He would whine at night before he would fall asleep. It was heartbreaking, really. He still does every once in a while. I know he misses her.”

But Leo certainly likes his new life, romping with his new canine pals and hanging out with the sweet delivery driver.

“He has so much personality, you would think that he is human!” says Newhouser. “He is the sweetest, most lovable dog that you will ever meet. ”

Mary Jo DiLonardo writes about everything from health to parenting — and anything that helps explain why her dog does what he does.