Scott Patton, a senior member at ZBrush Central, posted some stills of his work on Avatar.

The original post can be found here:
http://www.zbrushcentral.com/showthread.php?t=079195

“I started working on Avatar 3 years ago and was working with Zbrush 2 ( that means no subtools!!) I had to work on a fairly slow laptop so that I could work directly with Jim Cameron on the mocap stage.
I was really green as a 3D artist but jumped in with both feet, after all this time I still really love the stuff we produced at Stan Winston Studio / Legacy effects.

I was part of the group of artists that Designed the Na’vi characters I was responsible for working out Jake (Sam Worthington) and Neytiri (Zoe Saldana) Digital sculpts with expressions as a proof of concept for the look of the Na’vi people. I also did the designs for Norm (Joel Moore) as well as the Grace ( Sigourney Weaver}.
We also designed the Viper wolfs from a sketch of Camerons.
And fleshed out and detailed the head of the Banshee and figured out how it would function, that was a Neville Page design

Here are some of the Images that I did for the film Hope you like them, It was a long while ago, it’s amazing how far CG has come from way back when these were done.”

The images are too large to fit in the text area so here are links to the images.
Neytiri Facial Expressions NF_V-2_03
Neytiri Zoe Pose NF-S_V-1_002a
Jake Avatar Facial Expression JE-S_V-1_01
Jake Avatar JE-S_V1_02
Avatar Same eye-Chin Project 880
Avatar xsi screen grab Same eyes chin
Banshee New Vents New Jaw Bone V-6_01.1
Banshee V-6_02
Banshee Full Open New Vents V-6_05
Image – No Title Given
Avatar – Norm 3D Turnaround V-S_002
Project 880 Norm-Avatar
Avatar – Norm V-s-c_001
Avatar-Grace V-S-1_002
V-S-1_003
Avatar-Grace V-S-1_001