fat as a pig

*fat as a pig

exceptionally fat; grotesquely fat. (*Also: as ~.) If I don't stop eating this cake, I'll be fat as a pig! You really ought to go on a diet; you're as fat as a pig.
See also: fat, pig
References in classic literature ?
It was indeed Musqueton -- Musqueton, as fat as a pig, rolling about with rude health, puffed out with good living, who, recognizing D'Artagnan and acting very differently from the hypocrite Bazin, slipped off his horse and approached the officer with his hat off, so that the homage of the assembled crowd was turned toward this new sun, which eclipsed the former luminary.