I've had a really hard time drawing body folds (and I still do, tbh !), but Morpho: Fat and Skin Folds (book) is a life savior ! All Morpho books are truly godsent i cannot reccomend them enough !!
But personally when I draw Gale without any reference morpho included, I just go crazy and give him the tummy i'd like him to have on the moment (which changes a lot, sometimes i want him very soft, sometimes a bit skinnier, it's all about flavours !)
Hope this helped ♥