The following was originally posted on http://www.theguardian.com/childrens-books-site/2012/oct/02/writing-tips-animals-human-characteristics
"Jennifer Gray, author of the Atticus Cattypus Grammaticus Claw stories, which feature a loveable rogue cat based on her own pet, shares her tips for writing animal characters"
Animal characters demonstrate the full range of human characteristics. They might be kind, brave, greedy, cruel, selfish, ambitious, shy, confident, lazy, clever, hardworking, independent, fearful, resourceful or just plain silly. They may have particular attributes, like being able to talk! Just like humans, they will undoubtedly have to overcome obstacles in the course of the story. And they will probably learn a lesson or two along the way.
So how do you persuade your reader that it's perfectly acceptable for a bear to stop for a chat, normal for a toad to be hauled up before a judge, par for the course for a hamster to secretly sort out classroom crises, or a spider to write messages in its web (or for that matter for an increasingly cuddly cat to help humans catch a gang of magpies thieves), without resorting to that overused resource, "magic"?
1. Keep it real. Well, almost
What are the animal's perceived characteristics and reputation? This is a good starting point and can take you in all sorts of interesting directions. Is the animal really like that? If so, does it change? Set up conflicts for the animal to resolve. For example, what would make a cat compromise its independence – a chance of a permanent home maybe? Or you might prefer a reversal: a cat that isn't lazy but a workaholic, one that isn't a carnivore but a vegetarian. Play with stereotypes. A third alternative is to exaggerate the animal's known characteristics: the vicious feline with razor sharp claws that rips rats for a crunchy brunch.
2. Inhabit their world
Your animal character might be doing something amazing like saving the world from evil geniuses or something terrible such as plotting the downfall of humans; they might just be heading out for a picnic on the beach with the family, but at all times he or she has to be both credible and appealing to the reader. What makes them tick? What do things look like from their point of view? What are their perceptions of their surroundings, of other animals, and in particular, of humans? Get into their heads and look at the world through their eyes. Try writing a few scenes to test their voice. There's lots of comedy potential to be had in their different take on life. Atticus, for example, although he wants to go straight, will practically sell his soul for sardines. Ultimately, although they have human traits, the fact that animals come at things from a different angle is what appeals about them to readers of all ages.
3. Throw in some surprises
Challenge your character with some unexpected events or the arrival of an unwelcome visitor and see how he or she reacts. What characteristics do they display? Try giving them some unusual personality traits that you might not associate with a particular animal and see if it suits them. A marmalade-eating bear is utterly memorable.
4. Be clear how your character relates to humans
Their interface with the human world is probably the most difficult aspect of your animal character to get hold of. How do they do things? Do they communicate and, if so, how? Personally, I don't have any problem with talking animals, but it can be hard to convince. The more common formulation is that animals can talk to one another and understand humans, but humans aren't blessed with the same insight. Children are way more tuned in to the idea of animals as sentient beings than grown ups are, so letting your readers in on the secret when some of the (adult) human characters in the story don't get it is heaps of fun. Meanwhile your human characters reveal themselves by how they respond to the animal. Remember, they too can change!
5. Don't explain anything!
Whether you choose to let your animal talk to humans, like Toad and Paddington, or communicate in more subtle ways, like Humphrey, Charlotte and Atticus, you need to be clear, confident and consistent in your approach. Don't pause to explain. If it's well written, and your animal character oozes charisma, we'll buy it.