A troubled teenager who dreamed of becoming a lion tamer was mauled to death in front of horrified zoo-goers after climbing a 20-foot fence to get into the big cats’ enclosure. Gerson de Melo Machado, 19, snuck into the lioness’ pen at Brazil’s Parque Zoobotanio Arruda Camara in the city of Joao Pessoa on Sunday, scrambling over a wire-topped fence to climb down a tree inside the lions’ pen, Brazilian outlet O Correio Braziliense reported.