DENVER — Randy Boyum has been playing with clay for more than 40 years. "I dabbled in clay animation as a 12-year-old in the mid-1970’s, producing a few truly horrible short films," Boyum, now 58, ...

Caveman "Bob," a clay figure with blond hair and 1970s sideburns, strolls across the palm-tree jungle to examine a mysterious black box. When he gives the box a swift kick, the music of Metallica ...