You'd have to see it to believe it.
A kitten and a crow. A primate and a pup. Even a predator and its prey.
Defying the laws of nature itself, animal odd couples forge friendships under the most peculiar circumstances. But in the process, they show us that humans aren't the only members of the animal kingdom to demonstrate complex emotions and traits.
"To know that these animals are capable of emotions like love and understanding and caring, like we are, is quite an eye-opener," Tony Fitzjohn, a conservationist with Wildlife Now, says on a National Geographic program airing Saturday.
"Unlikely Animal Friends" features six of the most curious couples the animal kingdom has ever seen. Here are a few of our favorites.
One was an outgoing orangutan, the other an underfed stray dog.
But since the moment they met, Suryia and Roscoe have been inseparable.
Bhagavan "Doc" Antle, founder of The Institute of Greatly Endangered and Rare Species (TIGERS) in Myrtle Beach, S.C., said Roscoe, a Bluetick Coonhound, followed him and Suryia, one of TIGERS' orangutans, through the park's gate one day in 2006.
As soon as Suryia saw Roscoe, he ran over to him and started playing, Antle said. After a few unsuccessful phone calls to find an owner, Antle decided to let Roscoe stay.
Now, the pair has a ball frolicking around the park. For a few hours each day, they swim or roll around in the grass. Suryia will even grab Roscoe's leash and take him for walks around the enclosure, Antle said.
"To me, they seem like long-lost friends. They would make you believe in reincarnation," he said.
After a tsunami washed away his herd and stranded him, a young hippo found himself a most unusual ally: a 130-year-old tortoise.
The 2004 tsunami that devastated Indonesia also hit the eastern shores of Kenya. And after the storm left Owen, a small hippo, all alone, conservationists found a home for him in Haller Park, an animal sanctuary in Mombasa, Kenya.
They hoped that he could be a companion for a female hippo whose previous companion had died. But before they could introduce him to the other adult hippos (which can be aggressive and territorial), they wanted to give him a quiet place of his own to adjust.
And it was there that he met his buddy Mzee, an Aldabra giant tortoise whose name means "old man" in Swahili.
"He ran straight for the tortoise," said Sabine Baer, of Lafarge Eco Systems, which manages Haller Park. "The color is somehow similar like a hippo color. It was somehow round-shaped, so he must have associated it with an adult hippo and with his mother and his family."
At first, it was Owen who made the friendly overtures. But after a while, Mzee appeared to warm up to the heavyset hippo.
They slept together and ate together and even appeared to cuddle together. Owen would nuzzle Mzee's foot when he wanted to eat and Mzee would nibble Owen's tail to steer him.
"[Mzee] taught him to eat the cut leaves, he taught him to eat carrots, so for us, it was an absolute blessing to have that relationship to help us raise Owen," said Baer.
But though the pair became even closer and quite famous, inspiring a Web site and children's books, Baer and others worried that as Owen grew, he would put his smaller friend at risk.
So they decided it was time to move Owen into an enclosure with Cleo, the female hippo who had been waiting for him.