In an in-depth interview with Total Film, Hobbit director Guillermo del Toro lays out his vision for The Hobbit in detail and talks about how he plans to take creature design out of the shadow of The Lord of the Rings. In conceiving these creatures, he says he will "keep the DNA in the same gene pool as the Rings trilogy," but with some critical differences.
...in the trilogy most of the creatures are brutish or inarticulate. In The Hobbit, the creatures speak: Smaug has beautiful lines of dialogue; the Great Goblin has beautiful lines of dialogue; many creatures do. So we had to design them with a different approach because you are not just designing things that are scary.
I also wanted some of the monsters in The Hobbit to be majestic.
I wanted the Wargs to have a certain beauty so that you don't have a massively clear definition: what is beautiful is good and what is ugly is not. Some of the monsters are absolutely gorgeous.
Of course, the most anticipated of these creatures is the dragon Smaug. It's something that del Toro has been working especially hard on, and he promises something really unique here.
...we're finishing his colour palette and a little bit of the texture. But the bulk of the design took about a year, solid. It's because of the unique features of the dragon.
Early in production I came up with a very strong idea that would separate Smaug from every other dragon ever made. The problem was implementing that idea. But I think we've nailed it.
And then there are the spiders of Mirkwood.
Well, they are the progeny of Shelob, but Shelob was quite a promiscuous girl [laughs]. She mated with many partners. And insects and spiders are incredibly adaptable creatures. There will be spiders.... They are more creatures of the shadow, more creatures of the deep forest. They are not earth nesting. They are nesting in the canopies so physically they have adapted to that environment.... With Shelob, she was quite low to the ground so she moved like a tank. Our spiders have to feel massive but be very nimble.
What comes through most in this interview — which is well worth reading in full — is just how much fun making this movie is for him. And from all the hints he drops, it looks to be massively fun for the audience as well.