VISALIA, CA—Wedding attendee Marc Spanos was badly shaken Saturday when a conga-line participant ominously beckoned him to join the grim, undulating human chain. "This large woman in a pink, sequined dress started waving and gesturing for me to come get on the end," Spanos said following the ordeal. "It all seemed to be happening in slow motion, like they all had evil grimaces and were laughing in deep, slowed-down voices." Spanos dodged the encroaching conga spectre by spilling scalding hot coffee on his tuxedo pants. "That was a close one," he said.