I have a saying: Everything is better with cats.

The reasoning behind that should be self-evident. I mean, cats. So when I went to write The Forbidden Library, it was a no-brainer that there should be a cat. And the only thing better than a cat is a cat that talks. The wonderful thing about a talking cat is that you feel like you already what he ought to be like – sarcastic, but lovable; aloof, but not above a good belly rub.

The Forbidden Library's talking cat, Ashes-Drifting-Through-The-Dead-Cities-Of-The-World ("Ashes", for short) is the inheritor of a proud tradition of animal companions in children's fiction, so I thought I would go over some of my favorites. I admit that I have cheated a little; some of the "animals" below are not, strictly speaking, from children's books, or indeed from books at all. But they're all creatures I fondly remember from my own younger days, so here you go.

1) Mogget from the Abhorsen Trilogy by Garth Nix

In many ways, the archetypical talking cat. Sarcastic, sleepy, dangerous when angered, possessor of strange and mysterious powers. To this day I look at my own cats and wonder if they're the secret protectors of magical powers.

2) Pantalaimon from His Dark Materials by Phillip Pullman

The daemons are one of the most wonderful things about this fantastic trilogy, and the relationship between the bold, resourceful Lyra and the wiser, more cautious Pan is perfect. Their closeness makes you feel the bond the people of Lyra's world have with their companions.

3) Hedwig from Harry Potter by JK Rowling

You can't make a list like this one and fairly leave off Harry's faithful owl Hedwig. Unlike most of the animals on this list, she doesn't get to talk, but she becomes a beloved character all the same.

4) Tock from The Phantom Tollbooth by Norton Juster

Tock the watchdog exemplifies the role of the animal companion. He's a faithful friend and guide to Milo, providing sound advice throughout his adventure which his less careful human friend mostly ignores.

5) Kazul from The Enchanted Forest Chronicles by Patricia C Wreade

Whether dragons count as "animals" is probably a subject up for debate. Certainly I think the dragons would have something to say about it, including the one in The Forbidden Library! Also, Kazul would say that Cimorene is the companion; regardless, the friendship between the dragon and the wayward princess makes this one a classic.

6) The Death of Rats and the raven from Hogfather by Terry Pratchett

Do anthropomorphic personifications count as animals? Either way, Susan Sto Helit's guide and occasional tormentor the Death of Rats, with his translator/eyeball-connoisseur the raven, are some of my favorite characters from the endlessly entertaining Discworld series. SQUEAK.

7) A-Through-L from The Girl Who Circumnavigated Fairyland In a Ship Of Her Own Making by Catherynne Valente

A-Through-L is a wyverary, with a wyvern for a mother and a library for a father, and as his name implies he knows almost everything about subjects that don't start with a letter that comes after L. Like Tock, he is a faithful guide to his human, who usually doesn't heed his caution and gets into trouble as a result.

8) Dog from Good Omens by Terry Pratchett and Neil Gaiman

A small dog is the best friend a boy can have, especially when that dog is a recent convert from being a huge, black hellhound. Serving the Anti-Christ can be a tricky business, but it involves a great many more angry cats and fewer lost souls than Dog originally anticipated.

9) Bartimaeus from The Amulet of Samarkand by Jonathan Stroud

Bartimaeus is of course a demon – specifically a djinn – rather than an animal, but he spends a fair bit of time in the form of various creatures both real and supernatural. His snarky, sarcastic tone makes me think that he and Ashes would get along famously.

10) Totoro from Tonari no Totoro directed by Hayao Miyazaki

It's never exactly clear what Totoro is, except that he's big, fluffy, and a great friend to Satsuki and Mei. He's also well-connected among the weirder set, hanging around with woodland spirits and commuting via Catbus.