5. Cassowary Looks like a flamboyant, beautiful bird, but one of the most aggressive among the bird family.
The ostrich can be found wandering the rain forests of Australia and New Guinea.
It prefers to keep a low profile, but when disturbed this flightless bird can become extremely aggressive and territorial.
Capable of running and leaping at high speeds, the cassowary attacks by thrusting its large claws forward with the aim of disemboweling its target.