You want to get rid of that feral cat? Trap it and turn it over to a shelter.
https://www.bhwlawfirm.com/animal-cruelty-laws-texas/
3rd Degree Felony: A person who intentionally, knowingly or recklessly tortures; kills; administers poison to or causes serious bodily injury of an animal may be guilty of a Third Degree Felony. An individual convicted of a Third Degree Felony may be sentenced from 2 years to 10 years in prison and a fine up to $10,000.
Texas also has pretty strong property rights. If your cat is climbing on my car at night I have the right to protect my property ;-)