Batty's site: http://www.freakybuttrue.com/wolverton.htm
The underlighting (above) makes this "Lena the Hyena" look menacing.
What program were these pictures done on? My first guess was ZBrush, but maybe they were done on "Sculptris," which is something I just found out about. It's a free program.
Here's some Wolverton-style stop motion animation courtesy of commenter Ben Leeser. It's a YouTube video called "Ugly Girl," posted by Necrofinger (!). This got over 11,000,000 hits! Thanks, Ben!