# Are all fatty acids monocarboxylic acids?

The answer to this question might solve a multiple choice in my previous chemistry exam, which caused an argument with my teacher.

We know that fatty acids form fats and oil due to their carboxylic groups by forming triesters with glycerol. But is it possible to have a fatty acid with two or more $$\ce{-COOH}$$ groups to exist naturally? If so, is the property "fats and oils are neutral" just a general property, or does it have an exception?