TORONTO – When Colombian drug lord Pablo Escobar died in a hail of bullets, he left behind not just a broken drug cartel, but a quartet of African hippos. In the 1980s, Escobar smuggled four hippos into Colombia to join a collection of exotic animals at his multi-million-dollar estate outside Medellin. Left to fend for themselves in the wake of his death, these roly-poly looking, but extremely dangerous beasts (responsible for more deaths in Africa than lions or crocodiles) broke out. Today, breeding at twice their typical rate and with no natural predators keeping them in check, more than 60...