For part 1: https://www.furaffinity.net/view/39004896/

Azar's been getting a lot of data from his research, enough to even put together a handy chart! Clearly the root of his own gluttony must have something to do with what he percieves as a relation between happiness level and waistline size. This data all leads to a conclusion of CHONKS, which is an acronym known only to him and his notes. He's sure he's getting closer to some kind of breakthrough, but the exact kind of breakthrough remains elusive to him.
However, it's difficult to get accurate data when the subject he's trying to measure the waistline of, has their stomach grow even larger before Azar can even get a proper initial measurement! This could have disasterous results on the accuracy of Azar's research, and snowball all his data towards a conclusion that couldn't possibly make sense, such as Azar himself secretly loving being a tubby dragon! That's ridiculous! He's plenty happy being thin and fit as it is!
At least Mazh seems apologetic and understanding to dragon's plight. Yri, however, seems far more interested in just getting to the next bite of food.

Last part of the commission by and featuring both their character and

If you're looking for a part 3, it's located here. Azar's concluded his research and gone home to calculate stuff, but Yri and Mazh still had more food to finish: https://www.furaffinity.net/view/35391591/