The Real Science of Avatar
Jens Schlueter / AFP / Getty Images
On Earth: Mink
The lean body and graceful motion of the mink served as inspiration for the viperwolves. The minks' movement creeping so low as to almost disappear while hunting was mimicked in the scene in which a group of viperwolves circle Sam Worthington's character, Jake, in the forest.
Get the Latest Photos from Time.com
Get TIME photos and pictures of the week delivered directly to your inbox.