Kanae in Ojamajo Doremi. She's rather well adjusted though and does try to lose some weight in one episode.
The main character of Real Drive has two friends, a lithe and athletic one and a fairly pudgy one. However, the female body shapes in the series are actually surprisingly realistic, so the protagonist weighs enough that she could probably pass off as a Hollywood PudgyFat Girl in another series herself.
Incredible but true: Minako has been this for part of a chapter of Codename: Sailor V. All fault of the Dark Agency, that was selling incredibly addictive and fattening sweets... Thankfully Artemis caused her insecurities on her weight in time for her to not become really fat...
Apparently, her schtick is to constantly lose and regain weight. She can go from the picture above to model material, and then back, in less than a week.
Yugina in Attacker You! is very insecure about her weight, mostly because it hinders her a lot as a volley-ball player. Therefore, she's almost always sidelined when a serious match is playing. However, she smashes even harder than You herself due to being indeed the physically strongest of her team. Made even more ironic when her sister, who's quite not the twig and also a volley-ball player, is actually much more successful than she is.
In the Petshop Of Horrors manga there is a chapter where several people have storylines related to food and dieting. One is a high school girl who is chubby and wants to lose weight so that she can look pretty enough for a boy in her class to take her out to a dance. To the story's credit, she does learn that he was a jerk and that she shouldn't care what he thinks.
Millie the Model's friend Daisy is a relatively happy and well-adjusted example of the type.
Amanda Waller is another example of a large woman who is NOT insecure about her weight, and is plenty Badass. At least, she was, until the New52 reboot and the Green Lantern movie got a hold of her and retconned her into having a slimmer appearance.
Michelle, one of Andy's best friend's in How to Lose a Guy in 10 Days, who believes she's fat inspires Andy to write an article that is a How to in reverse about dating.
Han Na, the main character in the Korean film Two Hundred Pounds Beauty. She gets a ton of plastic surgery, and the rest of the film is about whether that was a net gain or loss for her ... pun slightly intended.
Agnes in Discworld has aspects of this, but only from an outside perspective. In fact, given that a major aspect of her personality is how irritating she personally finds the trope, it probably counts as a Deconstruction.
Brittney from Gone, books 2 and 3, although she is not comic relief and her weight is only mentioned once.
La Falvine from Malevil is an old fat woman. She is given considerable grief from a rival old woman who insists she is a burden to their limited food supplies after the Apocalypse.
Carmen of The Sisterhood of the Traveling Pants is a subversion. Her size and shape are an issue mostly because her Latina curves make her stand out from her father and his new family as seen when she gets so upset when her bridesmaid's dress doesn't fit because it was clearly designed for someone skinny. There's also the fact that she's the narrator and the one who holds the group together.
There's a racial element to it, too - one of the reasons why she gets so upset when her bridesmaid's dress doesn't fit is because it was clearly designed for someone like the newer, blonder family that her (also white) father seems to be replacing her with - a family that never got Carmen's Latina bottom genes.
Lois Waller of the Sweet Valley Twins series is a shy, overweight student who was once friends with popular student Janet Howell but now the only person who's nice to her is the kind-hearted Elizabeth.
Zev from Lexx grew up this way. She didn't have a lot of room for exercise at the Divine Order's factory farm for brides.
Lyndsay in Teachers. Notably she does get a romance storyline with Matt, the most conventionally attractive member of the cast, but only after an episode of him being shocked by his own attraction to her.
The Abc Family show Huge contains many fat girls (in fact most of the cast is overweight), but completely averts the stereotypes of the trope.
Lauren Zizes on Glee. She is presented as a really "cool" character but still often functions as the comic relief, mostly referencing eating. Because of hr toughness, Lauren could also be considered more of a subverted Brawn Hilda.
"Lucy Caboosey" (aka Quinn, before she got all that plastic surgery) is a straight example.
Harper from Wizards of Waverly Place is the best friend of the show's main character Alex Russo and is often known for her outrageous fashion ensembles that she designs herself. She is very optmistic, though a little insecure at times but not for her cloths which are generally non-figure-flattering.
Sookie St. James from Gilmore Girls is the loveable control freak and scatterbrain/klutzy best friend of Lorelai Gilmore.
Something of a subversion; while Sookie is skittish, her weight is never mentioned by anyone, she's never seen as fretting about being on a diet, and despite being a chef there's never a single "Ho ho, she should stop sampling her own products" crack made. The character could have been played by a woman of any size without having to be re-written (not that anyone but the awesome Melissa McCarthy should have played it), making her far from the usual "fat girl" type.
Theresa 'Terri' McGreggor of Degrassi is an insecure, overweight girl. Both Ashley and Paige's strong personalities completely dominated hers to the point to where she really could not stand up to them.
Darlene from 1000 Ways to Die's segment "Die it". She's so desperate to stop being this that she orders tapeworm larvae and swallows them so they'll eat up anything she eats. But since the tapeworm breed and spread inside of her, two months later Darlene loses both 27 kgs... and her own life.
Friends: Monica's Formerly Fat past is used for a lot of comic relief and a source of insecurity with her. An alternate universe episode also establishes that if she was still fat, none of her previous boyfriends would have dated her and she'd be a virgin. (Ouch.) Somewhat subverted eventually, when her normal world best friend-come-boyfriend is still her best friend and falls in love with her in the alternate universe as well.
Lulu Roman, formerly of Hee Haw, said in an interview about her casting in the show, "I was hired to be the fat girl I was."
Hilda in Shadow Hearts: From the New World in her curvy form. She has a hyperactive metabolism, and changes between curvy, slim, and bat forms depending on what she eats.
Princess Spumoni from Little King's Story. Almost everything she says revolves around eating. She even has a side-quest that involves gathering ingredients.
Princess Theredras, in the World of Warcraft dungeon Maraudon. She's also butt-ugly. Her mother, Therazane (ruler of all earth elementals) is almost completely spherical.
Many players make jokes about dwarf and tauren women being overweight. Oddly, the player consensus is that the human female model is also overweight, even though she's really just an example of Hollywood Pudgy.
This has led to something of a community backlash from those who don't hold that anyone who isn't a night elf or blood elf is overweight in recent years. Ditto for female dwarves, though not quite to the extent that female humans get defended.
The protagonist of Otometeki Koi Kakumei Love Revo is an overweight girl (as in 220 lbs) who used to be pretty enough to win beauty pageants, until her love of sweets did her in. The point of the game is to lose the weight while pursuing one of five hot guys (plus the pudgy childhood friend who gets hot later, and your brother).
Averted for Fat Princess. Making your Princess fatter to keep the other guy from making off with her is half the game. The other half is stealing his Princess.
Carrie from Everyday Heroes, although this is somewhat of an Informed Attribute. She isn't drawn that much heavier than the other characters, but a few have commented on her weight. If the comment comes from a rude guy, it's Hammer Time!
Faye of Questionable Content is considered this. She wasn't drawn any different from the rest of the rather thin cast, though she and other cast members would comment on her weight, until recently; as the artist's ability improved, Faye's curves became more apparent, though arguably not unattractive. The same could be said of Marigold.
Mostly subverted in that both are considered attractive by the other characters, largely because of their...ahem, assets. They even go out of their way to assure Marigold of this.
Both have other characters at some point pestering them to exercise and "improve" themselves. However, Faye manages to beat Dora at treadmill running when Penelope drags them to the gym.
The Empress of Blood in The Order of the Stick. She got wind that more powerful dragons have a distinct tendency to be bigger, so she decided that the quickest way to become more powerful was to gorge herself constantly.
Hanae from Red String, who is portrayed in a more positive light compared to most examples of this trope.
The Nostalgia Chick jokes that she feels this way about herself sometimes, so she has her own BFF (Big Fat Friend) Nella, whom she pays handsomely to be her "fat" friend so that she would look nice in comparison.
Winnie, aka Geomancer, in the Whateley Universe. She's overweight and shy and has a bad stutter (which gets worse when she's upset). She lives in a dorm at Superhero School Whateley Academy which is full of abnormally beautiful girls, and that makes her feel worse about herself. Fortunately, she has good friends who look out for her.
Mavis Cruet the fairy in Willo The Wisp. Most of the jokes are about the fact she can't fly.
Toot from Drawn Together. In one episode they even lampshaded that she just existed to be a one-dimensional fat joke.
Penny from The Mighty B! is the title character's clumsy, dim-witted, obese best friend, who loves taffy. Although she and Bessie are best friends, Penny also shows loyalty to Portia who is often opposing Bessie or trying to humiliate her.
In the TV series of The Little Mermaid, one of Ariel's sisters was retconned into a fat girl and she can be seen eating every time she appears.
Kurst the Worst from Recess. A rare example of being an antagonist (though she and Mikey become friends towards the end of the series).
Two-Tone from 101 Dalmatians: The Series is a minor example. She's not really "fat", just slightly chubbier than the rest of the puppies (except Rolly), and this isn't brought up at all in the series.
Meg from Family Guy fits this trope; while her girth pales in comparison to her father's and brother's, she is frequently taunted about her weight.
One of these is the subject of a song Stewie sings as part of a jug-band.
Stewie: Met 'er on my C.B., said her name was Mimi, sounded like an angel come to Earth. When I went to meet her, man you shoulda seen her, twice as tall as me - three times the girth.