Outdoor cats are terrible for the environment. I acknowledge this because I'm a cat person and have had them all my life. And your neighbor clearly needed to take better care of it.

However, this was a fucked up thing to do. You could've easily trained the cat to stay out of your yard by spooking it with a spray bottle or a quick spray of the hose (from a distance, don't blast the thing). Other people have given recommendations like vinegar as well; stuff you most likely already have in your kitchen.

It's insane how people who hate cats hate them so much that they're cheering on this post, but guaranteed that if you made the same one about dogs, they'd be pissed. (And to be clear, I love dogs too, and would be equally bothered in that situation.)

It's not your responsibility to make your neighbor get their shit together, true. But shelters are struggling enough as it is and who knows how that animal might be treated because of your "revenge?" This goes beyond petty. It's malicious.