Howdy!
This is Zbrush. A lot of our 3D artists use it to make very high resolution models (in the millions of polygons). Then we take that high rez model and do a process called retopologizing, usually in 3D-Coat, TopoGun or Maya. This process turns the model into a game asset which is in the thousands of polygons.
I actually cannot speak highly enough of Zbrush. Grumpy Monkey is the guy who showed me around Zbrush and helped me learn all the ins and outs. It's currently a big part of my pipeline, even as a 2D artist. It pretty much allows you to concept in 3D like you would play with clay. It's mind-blowing.
If you're just getting into 3D sculpting, try Sculptris, with is actually made by Pixelogic now, the makers of Zbrush.. which I just found out like.. a minute ago when I googled it. TIL.
http://pixologic.com/sculptris/
That's a great place to just start out and play. Zbrush proper is a very robust program which even professionals often just use a fraction of depending on specialty. Sculptris will be even more streamlined for the newcomer, and if you ever get really into it, you can always move onto Zbrush when your aptitude increases.
Also! Check out more of Grumpy Monkey's work! DISCLAIMER! The Singed you see on there is NOT an official VU. That was a demo Josh did for a conference.
http://vimeo.com/user8520235
