Dante's father from Dante's Inferno. Besides being a Jerkass to his son, he was a complete pig who wasted all of his family's money on wine, women and song. Predictably, when Dante encounters him in Hell, he's become a demon of Greed.
No More Heroes: Assassin No. 3, Speed Buster. Despite her apparent vagrancy...
Sonic the Hedgehog: Dr. Robotnik/Eggman is usually portrayed as this to excuse his gimmicky shape, but we've only ever seen him eat something once in the games. However, it involves him eating a submarine sandwich in under two bites, so it has some merit.
Mr. Luggs from Luigi's Mansion. You can hear his eating from the other side of the mansion, he shoots fire at Luigi and apparently ate himself to death by the age of 30. As the description says: He prefers all-you-can-eat buffets to three meals a day. He ate himself to death but still wasn't satisfied.
The Mr. Creosote lookalike in Ghostbusters: The Video Game, also known as the "Sloth Ghost." He's even worse than Slimer. If you read his description in Tobin's Spirit Guide, you'll learn he committed suicide by devouring a Thanksgiving meal for twenty people.
Borgan from Lunar: Eternal Blue. So fat he apparently has to have corridors greased to pass through them. Additionally, there are pictures of various characters in-game called bromides, and they usually show people in an attractive pose. Borgan's is bathtime.
Tengai Makyou IV features Madame Appetit, who leads a bizarre cult of gluttony out of Tombstone, AZ. She also proves to be an Acrofatic.
The monstruous demon lord Horkos from. Often eats his own underlings. Ate dozens of humans during his initial rampage. Wants to consume the entire world.
Not to mention his humble abode, Sector Carina of the Schwarzwelt. The entire dimension is modelled after a titanic shopping mall, with conveyor belts churning more and more food and luxury items, which are never enough to sate Horkos' eternal hunger for more.
Cursery's version of Humpty Dumpty was an aristocrat cursed with a ravenous appetite after Mother Goose gifts him with a magical (actually cursed) fruit.
Each of the Psychopaths in Dead Rising 3 correspond to the Seven Deadly Sins. Gluttony is represented by Darlene, a Fat Bitch on a scooter who tries to hoard a buffet for herself and stabs a man to death with a large spork for eating some of her food.
Zigzagged with King Hippo from Punch-Out!!. He's definitely a glutton, but he's far less malicious than most of Mac's opponents. (He even offers to take him out to lunch!)
Final Fantasy: Crystal Chronicles has an unusual take on gluttony. Raem, who subsists on memories (bad and painful memories in particular because they taste the best to him) in order to sustain himself. The spread of miasma throughout the world caused people to endure pain and suffering for a long time, which created painful memories. Because the Meteor Parasite is the source of miasma, Raem relies on the creature to keep producing it so that he himself can stay nourished through the sad memories. Mio, who is his counterpart, only nibbles on memories and can't endure the brilliant memories that the player character has. Both Raem and Mio are the reason why everyone in the world seems to forget things every so often, but Mio demands Raem to stop so people won't suffer any longer. Raem doesn't agree and wants even more memories to consume before proceeding to attack the player character.
An early RuneScape quest, "Let Them Eat Pie", features one of these named Rolo the Stout, who literally eats nothing but pies while the refugees in town suffer in poverty. You trick him into eating a rancid pie so the refugees can receive assistance.