The most intuitive word to describe a person rich in fat seems to be fatty. However, I'm not sure whether it's commonly used in a derogatory sense in English. Do I need a more appropriate word instead?
I would like the most common term to use in an everyday situation. For example, to tell a person from a group of people:
Tom: Who is Jack?
Jerry: The [fat/fatty/obese/...] guy over there.
Is calling someone fatty OK?