Papilio antimachus, also called African giant swallowtail, is the most poisonous butterfly in the world. It contains a lot of cardiac steroid toxins. The toxin in a male Papilio antimachus can poison 20 cats. The males have narrow forewings with a maximum wingspan of 25cm, ranking first among all the male butterflies. It is also the largets butterfly in Africa. It is found in Uganda, Zaire, Angola and Sierra Leone.