11/19/2010 09:22 am ET | Updated May 25, 2011

Oddest Animal Companions

Sometimes animals that wouldn't normally socially interact break the mold and become friends, transcending or ignoring instinct and how science says they should behave. These are often some of the strangest stories from the animal world.

Usually, these odd animal companions involve cases of mistaken identity, adoption of an orphan of one species by a female of another, or wild animals that have been raised by people. They are almost always heart-warming to watch, although some of them will make you laugh, some will freak you out and others are real tear-jerkers.

Here are my top 10 odd animal companion stories.

1. Elephant Seal and Woman
Wildlife biologists try not to interact with the subjects of their research for fear of altering natural behavior. But if the wildlife decides to approach and befriend the researcher, there's not much you can do but enjoy the experience!

2. Deer and Cat
This rescued deer, named Hoppy, has befriended a domestic house cat that shares his home. Hoppy is not at all shy about enthusiastically showing his affection to the cat.

3. Polar Bear and Sled Dog
I have no explanation for this shocking but ultimately both awe and "awwww" inspiring example of odd animal companions. Sometimes the enmity of animals that would normally be natural enemies fades away in the face of fun and companionship.

4. Monkey and Pig
In this case, two very different orphaned animals at a zoo have formed a bond in the absence of parents and siblings of their own species. As you can see (at least from the monkey's perspective) they are stuck together like glue.

5. Orangutan and Dog
In a strange but touching example of two totally different species that for some reason decided to be friends, Suriya the orangutan and Roscoe the dog are inseperable.

6. Hippo and Tortoise
This case of odd animal companions has gotten major media coverage and there's even been a children's book written about them. A hippo orphaned by a tsunami found a mother figure and best friend in the unlikely form of a giant tortoise.

7. Cheetahs and Impala
Cheetahs normally prey on impala, an African antelope species. These cheetah siblings, however, didn't get that memo. Instead of eating this impala, they befriended it.

8. Crow and Kitten
What caused this crow to adopt a kitten as its own, we'll probably never know, but it sure was lucky for the cat.

9. Dog and Elephant
There's no way you can hear the story of Tara the elephant and Bella the dog and not feel the tears welling up. Along with Owen the hippo and Mzee the tortoise (see #6 above) these two are the most famous of odd animal companions.

10. Lions, Tigers and Bears These three predators are naturally found in very different places and would never interact in the wild. The lion comes from Africa, tigers are found in Asia, and the black bear is the species found in North America. Yet in captivity they've formed a fast friendship.