It's not the best I know of, but it is still new(as in four days old).
http://www.deviantart.com/deviation/52597581/
It was drawn by this artist known as "Twilight thorn", he also has a few other fairly decent fat-girl pictures in his gallery and scraps.
<.<
>.>
now if you'll excuse me, Extreme ghostbusters is callin' to me.