With a history extending back millennia, with a biology that leads to permanent disability for tens of millions of people globally, and with a bacterial endosymbiont that may prove to be its Achilles heel, the filarial parasites that cause lymphatic filariasis are quite the complex creatures. In this episode, we explore the intricacies of this neglected tropical disease - also known as elephantiasis. We start by examining its complicated ecology involving many mosquito and parasite species, before moving on to its tricky biology where we finally answer the age-old question, “What is the lymphatic system anyway?”. Next, we move on to the convoluted history of lymphatic filariasis, where it holds the distinction of being the first disease recognized as mosquito-borne. We wrap up the episode with a look at its present global status, grappling with some current figures on the tremendous global burden of this disease and investigating some exciting treatment developments that will hopefully bring relief to the hundreds of millions of people at risk of developing this debilitating disease.