Naturally, all of these pictures are heart-breakingly adorable, but there's more to it than that. Why did these animals form their friendships? Some of them, like the lions, dogs and elephants, are known for forming strong social relationships or even networks in the wild. In the absence of their prides or packs, it makes sense that they would seek social relationships outside of their own species. Other more solitary animals may form parent-child relationship with animals that they spend time with or that helped raise them, especially if their own parents are gone.

Whatever the reason may be, unusual friendships like these show that animals may be far more emotionally complex than many of us believe. Maybe these friendships aren't so unusual after all! Meet Bubbles the African Elephant and Bella the Black Labrador.

Despite the extreme difference in size, Bubbles the elephant and Bella the black lab have become great friends. Bubbles was brought to a safari reserve in the U.S. after she was rescued from ivory poachers in Africa, while Bella was left there by a contractor for the park. The two are great to see together, especially when Bella uses Bubbles as a diving board! Image credits: Barry Bland

Bea the Giraffe and Wilma the Ostrich: Bea and Wilma have become great friends during their time together at Busch Gardens in the U.S. The two share a huge 65-acre enclosure, so they aren't forced to spend time together – they do so willingly. Image credits: PA

Tinni the Dog and Sniffer the Wild Fox: Tinni the dog and Sniffer the wild fox have been the best of friends since they met in the forests of Norway. Torgeir Berge, Tinni's owner, does what he can to keep up and photograph the pair as they play in the woods. Tinni lives with his owner photographer Torgeir Berge in the forests of Norway. Image credits: Torgeir Berge

One day, while they were on a walk together in the woods, they met a wild fox that they named Sniffer. Despite the thousands of years of breeding and the social circumstances that stood between them, they became the unlikely animal friends. Now, Berge follows the cute couple around as they romp and play through the woods. Fortunately for the rest of us, he brings his camera along to capture the shenanigans of these animal friends. The way the two adorable animals play together reminds us that wild animals, which many of us fear or disrespect, can be far more similar to the domesticated animals we love than we thought.

Torque the Dog and Shrek the Owl: Torque adopted Shrek the owl chick when he was just 6 months old himself. Shrek was removed from his mother's care because handlers were afraid that she might eat him when stressed. He's doing great now, and the two have become inseparable pals. Image credits: Solent News and Photos

Fred the Labrador and Dennis the Duckling: Things were looking grim for Dennis the duckling when his mother had been mauled by a fox. Fred the Labrador and his owner Jeremy, however, found and rescued Dennis. Dennis and Fred have been buddies ever since. Fred apparently has a big heart, because it's not the first time he's helped take care of an orphan – he once adopted a baby deer as well. Image credits: SWNS

Mabel the Chicken and the Puppies: After being saved from the pot due to a foot injury, Mable found a new wonder when she was moved into her owners' home – puppies! For some reason, the year-old hen has taken to roosting on the puppies and keeping them warm while their mother prefers the yard. Go figure. Image credits: Anita Maric

Milo the Dog and Bonedigger the Lion: Milo the tiny dachshund took Bonedigger the lion cub under his wing when it was discovered that the lion was suffering from a metabolic bone disease that left him disabled. Five years later, the 500 pound lion is still the best of buddies with the 11-pound dachshund and his two compatriots, Bullet and Angel. Image credits: Barcroft USA

Cat and the Fox: This curious pair was spotted playing by fishermen on the shore of Lake Van in Turkey. Not much is known beyond the fact that they're very cute and very playful. Image credits: imgur.com

Shere Khan, Baloo and Leo: The tale of Shere Khan the tiger, Baloo the bear and Leo the lion is truly touching. The three of them were rescued together from a drug dealer who had abused them extensively. Baloo even needed surgery to remove a harness that had grown into his skin and caused deformities – the owner had never bothered to adjust it. Because of what they've suffered together, the three friends are now inseparable. They are under the care of the Noah's Ark Animal Sanctuary in the U.S. Image credits: Barcroft Media

Mani the Wild Boar Piglet and Candy the Dog: Manni the wild boar piglet was found starving in a field in southwest Germany and brought home by the Dahlhaus family. When he was introduced to their Jack Russell terrier Candy, the two immediately hit it off. Since last we heard, Manni is recovering well and will either stay with his family or move to a wildlife park. Image credits: spiegel.de

Kasi the Cheetah and Mtani the Labrador: Kasi and Mtani were raised together at Bush Gardens in the U.S. During their youth, their unusual friendship was a treat to watch. As he grew into adolescence, however, Kasi began drifting away from Mtani and becoming more interested in the female cheetahs in the next pen. While Kasi now spends more time with other cheetahs, the two are still good friends and often visit schools and other places together. Image credits: Busch Gardens Tampa

Rabbit and Deer: Spotted by animal photographer Tanja Askani, this unusual deer and rabbit duo looks like right out of Disney's classic Bambi. Image credits: Tanja Askani

Suryia the Orangutan and Roscoe the Blue Tick Hound: Suryia and Roscoe live together at a rare and endangered species reserve in the U.S. While orangutans are endangered, dogs are certainly less so. However, Roscoe has lived with her ever since he followed Suryia and her handlers home. It didn't look like he had any other home to go to, so he stayed with Suryia, and they've been great friends ever since.

Kate the Great Dane and Pippin the Deer: Pippin the baby deer was adopted by Kate the caring Great Dane. They were great friends while growing up, but as Pippin matured, she moved out into the forest to raise a deer family of her own. She still visits Kate and her owner Isobel, however. Image credits: Isobel Springett

Anjana the Chimpanzee and Tiger Cubs: These two white tiger cubs were separated from their mother after her enclosure was flooded during a hurricane. Fortunately, they've been adopted by a U.S. animal reserve by Anjana the chimpanzee and their caretaker, China York. Anjana has helped China raise many different orphaned animals, so we're sure they're in good hands. Image credits: Bary Bland