I guess it comes down to the fact that there aren't many Arabs who live in the Philippines, so we don't have as many epithets associated with them.
It's not that Filipinos have no cultural interaction with the Arab world -- in fact, there's an overwhelming majority of overseas Filipino workers in the Middle East, who remit their salaries back into our economy, to keep it afloat. But if any of them ever came up with racist terms to describe the citizens of their host countries, I certainly don't know what they are.
On top of that, "coon", as a cuss word, is American in origin, yes? Since there are very few black people living in the Philippines, we don't really come across a lot of phrases derived from "coon" (or, for that matter, the "n-word").
