DAZ makes a couple of amazing and free 3D animation software. DAZ 3D lets you play around with animated figures and settings. You can buy premade elements - like playing house - and piece them together to make your own image. Bryce lets you build entire worlds. Bryce 6 is for sale but Bryce 5.5 is free.
Our very own Cannes guest blogger, Robert Pratton, filmmaker of Mind Flesh, made his own fun video as part of his marketing push for Mind Flesh. He bought a dog from DAZ, then used an alternative program, Poser, to animate it. (See how making these extras gets you publicity?) Check it out.