3D Animation - zBrush
Introduction to the "zBrush" Software
What is zBrush?
zBrush is a 3D program with a focus on digital Sculpting.
Other programs such as Blender also have sculpting capabilities. But at least for now, zBrush tends to be the most powerful and most commonly used by industry professionals.
For more info see the zBrush vs Blender comparison.