Lonomia obliqua (or Giant Silkworm Moth, a name also used for a wide range of other Saturniid moths) is a species of Saturniid moths from South America. It is famous for its larval form, rather than the adult moth, primarily because of the caterpillar's defense mechanism, urticating bristles that inject a potentially deadly venom. The caterpillar has been responsible for many human deaths, especially in southern Brazil. Its venom has also been the subject of numerous medical studies.