Single-wattled Cassowary (Casuarius casuarius unappendiculatus), also called the Northern Cassowary. Cassowaries are very large, flightless birds native to the tropical forests of New Guinea and northeastern Australia. They are frugivorous; fallen fruit and fruit on low branches is the mainstay of their diet. They also eat fungi, snails, insects, frogs, snakes and other small animals. They are considered the world's most dangerous birds and one of the most dangerous animals to keep in captivity, based on the number of injuries to zookeepers. Papua New Guinea.