Why woould you want to throw a cat
Welllll....let me try a few ideas on you:
1. Back in the 90's there was a shareware program running around that was a skeet shooting game with cats instead of clays (with proper sound effects). It was damn funny provided you set aside your empathy for a few minutes.
2. Maybe you can launch the stray neighborhood cats into the next neighborhood over.
3. Attach metal claws to their paws and launch them over the wall! If you can figure out how to get the cat into the basket without causing more damage to your own people, surely you can figure out a way to break its fall on the other end.
I thought about the incendiary bat bombs from WWII, but I'm not sure that would work with cats any more than just jugs of flammables.
4. If you can make it accurate, maybe you can turn it into an anti-homing pigeon system.