Fat would have to prove that a fictional character saying the same words in the same order as one of his tweets is financially damaging him, somehow.
If anyone actually owns the copyright to tweets, it’s probably twitter anyway.
This I am just guessing but I can imagine that it’s somewhere in their terms and conditions.
On an unrelated note, I have been penning a parodic character based on everything Hunter S Thompson wasn’t.
Patrick S l Tomlinson, my fictional character, where Hunter is skinny, Patrick is fat, where Hunter is competent with firearms, Patrick pretends to be good with them, where Hunter is a gonzo journalist who rode with the hells angels and took a rightfully earned beating from them, Patrick is a cowardly bar fly who is more mouth than trousers.
The only common thing is their alcoholism and unpredictable nature.
If this happens to bear any likeness to anyone else named Patrick, well it is a total coincidence.