The Macellariusbloodline from Vampire: The Requiem. Their nickname is "Gluttons." Once someone's initiated into the bloodline, they gain up to 150 pounds in the next few nights. Oh, and the bloodline is made up mostly of cultured gourmands with a special taste for long pork.
In Dungeons & Dragons, amnizu, a type of powerful devil, are like this. Not only are they are obese and ugly, they act like snobbish arrogant, haughty aristocrats, even towards devils weaker than themselves, whom they look down upon. The ones under the sway of Levistus, the Lord of the Fifth actually think that the laws of Hell don't apply to them (because Levistus told them that; of course, the same type of thinking got him in trouble).
Dominar Rasheth from Skorne Empire is one, deliberately going against the Proud Warrior Race code of his people and loving it.
In the Succession Wars era of BattleTech, the Draconis Combine's Dieron Military District Warlord, Vasily Cherenkoff, is notably overweight. Personality-wise, he is described in less than flattering terms as abrasive and barely competent, an intersection of a Glory SeekerMiles Gloriosus, The Neidermeyer, and Colonel Kilgore, feared and despised by his men, such that the leader of the Combine's Secret Police summed him up in disgust as a "fat fool." While he piloted a 100-ton Atlas, even that got him no respect, as his troops quietly joked it was the only 'Mech he fit in, and that the 'Mech's hips were giving out. He even went so far as to go rogue from his own government to pursue a war he thought they wanted but did not sanction. He eventually got what was coming to him.