Kitty vs Alien (Feral Aliens)

When I catch my neighbor trying to steal my cat, I do what anybody would do.
I hit him with a spade.
That's when I discover my mild mannered, cute, but boring neighbor is actually an alien. With fur. And claws.
He doesn't work in finance, either. He's an interstellar bounty hunter.
According to him, I've been aiding and abetting a fugitive in the form of my cat, Mr Tiddles.
When I refuse to give Mr Tiddles up, I find myself dragged before a merciless alien court.
I have no chance of beating the charges, and the sentence is not what I expected.
I become the bounty.
I become his chain-kept.
I become the alien's kitty.