Later, at a roadside pancake place the girls stop at on their road trip Grace became one of only four people to eat the Pancake Mt. Doom Meal. This consisted of a dozen flapjacks, a variety of fruit fillings, sides of bacon, sausage, hashbrowns, three kinds of syrup, and your choice of eggs. The best part is that "Andy Debtman, Eater of Food" from Man Engulfs Food arrives to take on the challenge, and stands in front of the Wall of Fame filming his introduction while Grace's photo is added.
If you see carefully, the Beat Panel has Andy still staring in the same direction after she ate the Mt. Doom Meal, had her photo taken and put on the wall. Implying that either he's that stunned, she consumed her mountain before other girls finished their sane portions, or she continued to eat.
In Gnoph, hosts to Gnoph symbiotes have to eat large amounts of food. If they use too many Gnoph powers without eating enough, the Gnoph will start to consume body tissues for energy. Abbey, who grew up homeless and was therefore never able to get enough food, is anorexic to the point of Body Horror.
Molly and Galatea, the pink furry peanut butter monsters in The Inexplicable Adventures of Bob! both have very high metabolisms (they grew from infancy to maturity in a month's time, and are fleet-footed enough to outrun a bear at full gallop) and will eat enormous quantities of any kind of food. Molly has reservations about eating peanut butter, though, saying it makes her feel "kinda cannibalistic".
General Protection Fault: Fooker is well-known for having a truly rapacious appetite at times. Normally, he seems to have standard desires for food, but when it comes to some kinds of junk food, especially pizza, he can put enough away to put the Flash to shame. He's twice now nearly driven a pizza place (run by the same guy) out of business due to eating all of their merchandise and earned multiple lifelong banning for it.
Craving Control's lead character was a coed named Lalia, who was implied to acually have a binge eating disorder, but you wouldn't know it from her slim, extremely busty figure. This was eventually subverted as in one of the last strips, eighteen years of overeating finally caught up to her and she woke up with thicker hips and a noticable pair of love handles. Guess she finally ran out of room for fat in her breasts.
Robin DeSanto of It's Walky! eats tremendous amounts of candy, as a justification of her Super Speed. Both her Super Speed and Big Eater habits have been played down (But not removed!) since she moved to Shortpacked!.
Walky had occasional Big Eater moments as well, usually involving his favorite snack food DoritosNachitos. At one point it's revealed that this is all Walky ate back then.
Joyce also eats more than she should be able to and maintain her figure. When Walky eats similarly, he starts to gain weight.
Seekers: Giselda will scarf anything that is set in front of her. Especially when it doesn't belong to her.
Dee from PHD, who even sneaks out in the middle of an exam to get food.
Iki from Off-White likes to wolf his food down. It's a wonder his pack mates tolerate this behavior, considering he's useless when it comes time to hunt.
Thaumaturge: Befitting a webcomic that prides itself on its Shounen roots, Nomen's appetite is through the roof.
Too Much Information: the kittens. They're just ordinary sized kittens, but there doesn't seem to be any limit to how much they can consume. Nor do they appear to have much in the way of discrimination, either, since they'll happily devourer anything in the kitchen.
Very early in The Senkari Freija apparently eats 3 Burgers without breaking stride. Possibly justified as being a full time Action Girl she burns through a lot of energy.
Jeremy from Split Screen. Eats as a coping mechanism. Weight fluctuated through the comic's run, but was never below "pudgy" - save for flashbacks.
It's Impossible to Tell
Professor North Dakota Jones of Irregular Webcomic!, who goes to an "all you can eat for 150 lire" restaurant in Rome and gets 300 lire worth. You can't tell which heading he's under because he's Built with LEGO and thus appears to have exactly the same build as every other character in the "Cliffhangers!" theme.
Princess Kaira from Restaurante Macoatl switches from being chubby to being thin depending on the storyline.