The tábano is a biting insect of South and Central America. It's like a gadfly or horsefly with a particularly painful bite. And they are determined; once a tábano has you in its sights, you can't get away; you have to kill it quick.
Most other biting insects have a syringe-like proboscis, but the
tábano has a serrated one. They are vectors for various blood-borne illnesses like encephalitis.