>>59038589May is an easy one as this anon said
>>59038609 She eats a lot, loves food, has a curvy figure and her design is overall pleasant to see fat.
I also like to see Mallow as a fattie because she genuinely gets fat in canon once (not quite, but it counts).
Honorable mentions to Sabrina (it's in fact a meme here), Flannery and Skyla (any girl who exposes her belly should be fat), Whitney (Miltank comparissons go brrr), Clair (is satisfying and sexy seeing an arrogant bitch get plump and fat and see her ego crumble) and Mina (cause fat stoner girl is a hot concept)