The descendants of the hippos owned by drug boss Pablo Escobar are causing uproar in Colombia. The head of the Medellín cartel had established an illegal private zoo on his hacienda. After Escobar died in 1993 during the drug war, the estate was cleared. Four hippos, hidden in the lake of the hacienda, were overlooked and have since then they have multiplied rapidly in the Río Magdalena, one of the largest rivers in Colombia. The animals, weighing three tons, are displacing native species such as otters and manatees and can also be dangerous for humans.