Jack Hanna has hosted TV shows about wildlife since the premiere of "Jack Hanna's Animal Adventures" in 1993 and has become a zoological authority in his 30-plus years working at the Columbus Zoo and Aquarium in Ohio. On "Wild Countdown," he uses his knowledge and experience to present count-down lists of rare, fascinating creatures -- appropriate, given Hanna's many appearances on "Late Show With David Letterman." Topics include beasts equipped with armor, deceptively cute -- but dangerous -- animals, and adorable baby critters.
