Deadly Battle, happens every 5 moons. Basically half of the clan will die.

Attack,below is what can attack and what happens when its not defeated.
Birds, they can take prey, herbs, sticks and cats.

Rouges, they can take prey, herbs, stick and cats. They also can do anything to the cats they take.

Horses, rare but extremely dangerous they can crush cats and dens.

Dogs, they cab attack cats, destroy dens, take food and possibly settle on the territory and have to be chased off.

Badgers, same as dogs.

Natural disasters, these can happen not all of them can of course but I won't tell you witch ones can and can't.