It completely slipped my mind, but you're absolutely right. Frog is a fine ethnic slur and shall be included. Frog-eater is a tougher choice, because while the expression is popular in some European countries, it doesn't seem to have much circulation in the English language.
Surprising that you haven't included frog in this list. As I expect you know, it's a slur for someone who is French or French-Canadian, and I think it comes from the stereotype of such people eating frog legs.