Tyron_Leung Do you mean The Rat King? If so, then yeah, I could see him being a horror/slasher esque anti-villain of sorts (since he wasn't THAT evil in the Mirage comics) in a movie. However, I think Rat King needs something to bounce off or else it's just going to be a lot of dragging for an 1/2.
I know people mention Baxter for this, but meh. I don't buy it. There's nothing to go off except the whole "Mouser eating rats that conveniently connect to the Rat King". The Rat King is supposed to be this delusional man who takes up multiple monikers to try and scare off intruders of his home. Later, he becomes a mystical savant of sorts. I don't think people realize how contrived this would take to make it work in a movie.
Personally, Rat King shouldn't even be a antagonistic force to the Turtles specifically. I would like to see his role be inspired by his City at War appearances.