Eagles: Eagles have been known to hunt cats from time to time. They usually target apprentices or smaller, lone cats.
Dingoes: Dingo packs rarely make their way into Stormclan's territory on behalf of how difficult it is to get in or out, but the occasional solitary dingo has found its way into the valley now and then.
Quolls: Though not usually aggressive, quolls that make their home on the territory will sometimes attack cats that wander too close to their dens, especially at night. They're unlikely to do significant damage to any experienced cat.
Opossums: Possums are not often a threat to Stormclan cats, but a particularly moody or threatened one may try to attack a cat. Though most warriors could handle one, these fights can prove dangerous.
Kangaroos, Emus, Deer, etc: Though not outwardly aggressive towards cats, these animals can prove dangerous if spooked and can trample cats.
Snakes (Ringed/Western Brown): Venomous. Patrols are occaisonally sent out to kill the things. Only experienced warriors are allowed to go.
Pythons: Will attack cats when particularly hungry.
Sand Goannas, Perenties, other monitors: Hiding out in burrows, these monitors can be very dangerous to cats, especially those wandering alone. With some venom in their bite and dangerously strong tails known for crippling limbs, they're a serious threat to be avoided.
Cane toads - Poisonous if accidentally eaten. Often killed and left for scavengers when there's too many about.
Stingrays, Pufferfish, Sea Snakes, Octopus: Just don't mess with it and you're typically fine. Will rarely be aggressive naturally.
Sharks - Very uncommon for cats to be attacked by sharks. They just don't care.
Most water-dwelling "threats" won't attack cats unless provoked first.
General threats (environmental)
Earthquakes
Tsunamis
Cyclones
Rockfalls/landslides/etc
Cave-ins
Crabs (Takes expertise to hunt)
Birds (Soooo many just ask)
Mice
Echidnas (rarely hunted due to their spines)
Bats
Lizards (Geckos, Thorny Devils, long-nosed dragons, Dtellas,)
Sea turtles*
Technically if you're ballsy enough any predator can be prey i guess
Fish
*Turtles are really only hunted for sport