My last one for today.. Cassowaries are flightless birds of the genus Casuarius. Cassowary kicks are powerful enough to break bones and kill. Cassowaries are heavy birds and can weigh up to 157 lbs. When they kick, the kick downwards, so the full force of their weight is behind their kick. Cassowary kicks are also dangerous because they have claws that can grow up to 5 in.