The infamous drug lord Pablo Escobar was notorious for smuggling cocaine all over the world. With his drug money and power he illegally imported an array of exotic species to his personal zoo. But soon after Escobar's demise, the animals were left alone in the zoo to fend for themselves. One of these species flourished and now lurks in the Colombian countryside. As a dangerous and potentially aggressive invader, hippos are claiming territory in the rivers of Colombia. Join National Geographic WILD for an exclusive look at the so-called 'cocaine hippos' and the battle to try and control this thriving African visitor.