Your venomous serpent bites you, and the clock is ticking. America’s zookeepers—and a cooler full of rare antivenom—are your best chance of survival. Animation: Jacqui VanLiew; Daniel Arnold; Getty Images The first thing Chris Gifford thought as he felt a fang sink into his skin was: I’m going to die . The second: I need to start a timer immediately. That day in 2021, Gifford was cleaning the enclosures of the several dozen snakes he kept at his parents’ home in Raleigh, North Carolina. Nearly every snake in his possession was both venomous and native to distant corners of the world. Sharp-nosed vipers, eyelash vipers, forest cobras—every one of them beautiful, and many of them lethal. So too was the 7-foot-long, electric-hued western green mamba that had just latched onto its enclosure’s swing door as Gifford attempted to pull it out with a hook. The snake then lunged off and bit into Gifford’s hand, unleashing a deadly neurotoxic venom into his body. “I dropped the snake,” Gifford says.…