1 Southern Cassowary
The Southern Cassowary is considered to be the most dangerous bird in the world which is known for their aggressive nature. Common to New Guinea, these flightless bird has a 5 inch-long dagger-like claw attached to its second claw. The cassowary can charge up to 30 miles per hour and leap more than 3 feet in the air. If threatened, a Cassowary can maul a human and do an incredible amount of damage with just one kick.
Endemic to Africa, Ostrich is the largest living species of bird in the world. Ostriches can run up to 45 mph and can be as big as 9 feet and 350lbs. These large flightless birds have large leg bones and hoof- like sharp and pinted nails that can kill humans in just few seconds.