Cassowary

Native to the tropical forests of New Guinea and northern Australia, Cassowaries are large flightless birds with not so aggressive nature. However, if angered, they can be extremely dangerous.

Ostrich

Large in size, Ostriches are known for their strong, long legs, which they use to protect themselves from predators.

Emu

Emus also have powerful legs that they use in their defence when threatened. Their strong kicks can cause serious injuries.

Lammergeier 

Lammergeier aka bearded vultures are big size vultures that primarily feed on dead animals. These birds are not considered dangerous to humans.

Found in America, these owls are known for their aggressive nature. With sharp talons and a powerful grip, they are considered dangerous to humans.