I’m letting out my inner zombie, and I think you should, too! This brilliant little demo by Steve Wittens uses a pair of large sprite sheets (one for colour, one for opacity) which contain the cross sections of a human head taken by an MRI scanner.
CSS 3D is something of an unsung hero, I feel. Despite having been implemented in Chrome, Safari, Firefox (and the incoming Internet Explorer 10) as well as iOS and Android devices there are surprisingly few demos out there showcasing its abilities.
All together now: “Brrrraaaaaains!”