Big Brother Mentor / Older and Wiser: Chuckie has an odd role when it comes to wisdom: most of the time he's nebbish and insecure, but when the moment comes for it he's also often the guy who picks up on his friends' sensitive/emotional problems and gives wise speeches to members of the gang, most often to Tommy and Kimi. Occasionally he's the "lesson giver" when Susie's not around.
This leads to a Running Gag where Chuckie gives some insightful advice, and then admits he got it out of a fortune cookie / hallmark card.
Funnily enough, while Chuckie often fills this role for Tommy, Tommy often fills this role for Chuckie. It's a cornerstone of their friendship. In fact, a couple of the speeches he gives to Tommy are of the "teaching a lesson that Tommy didn't realize he was already inspiring in other people" sort.
Bad Liar: Angelica basically has to drill him in how to be an effective liar.
Blind Without 'Em : Not as bad as in the original series. He actually removes his glasses at times to read fine print.
Butt Monkey: Even more so in this series. One episode even finds him completely naked on school grounds, save for a guitar.
Continuity Nod: The circus camp episode reveals that even after all these years, Chuckie's still terrified of clowns.
Crouching Moron Hidden Bad Ass : He often displays abilities that end saving the day, and when facing his fears he actually proves himself a quite competent leader and hero. Unfortunately, many of his abilities only work in very specific circumstances, a constant source of frustration for him.
Heterosexual Life-Partners: With Tommy, of course, and even gets jealous if anybody threatens to take his place as his best friend.
Hidden Depths : In 'Superhero Worship', it's revealed Chuckie has a knack for engineering; his design for a mice labyrinth (required for a school project/contest) was so good that its photo and blueprints appeared in a specialized magazine, and one year later, when helping Tommy do his own labyrinth for the same project, they won first place. Later, in 'Brothers' Grimm', this ability is referenced again, as he makes the blueprints for a treehouse, having professional-like quality.
Shower Shy: An episode has him trying to avoid having to shower in gym class, until one of his attempts to do so gets him stranded outside the locker room with no clothes or towel. At the end of the episode he finally overcomes his fear.
Simple Yet Awesome : Apparently, he doesn't consider his latent engineering skills to be cool or impressive at all, since he never told anyone about how his mice labyrinth's design actually got shown in a specialized magazine, and his friends only found out when looking for reference material for their own labyrinth. It's possible that Chuckie has other cool or useful abilities but he doesn't consider them interesting at all and therefore never shows them until they are actually necessary.
A similar case in 'Dude, Where's My Horse?", when he finds out he's an extremely good cowboy, but then feels bad when remembering these abilities are useless back at home... and then he starts playing a harmonica with remarkable skill. Even Tommy can't make him confess at what point he learned to play an instrument, as Chuckie himself apparently learned to do it almost without realizing it.
Techno Babble: Descends into this when he's deprived of television. "TV Rots Your Brain!" indeed.
Why Did It Have to Be Snakes?: While Chuckie has gotten over most of his childhood fears (even his fear of Angelica!), he never quite got over his fear of clowns.
My Sister Is Off-Limits!: When he finally learns the biological differences between him and his sister, he becomes overprotective of her and chases off a guy hitting on her.
The Pig Pen: Obviously not to the extent of Rugrats, but he'll still engage in gross behaviour now and again.
Real Men Wear Pink: Wound up in a cooking class full of girls and demonstrated a real talent for it. He only gave up cooking because he learned there were health codes to abide by (such as washing hands).
Running Gag: If Phil's wearing a hat, expect it to be gone by the end of the episode.
All Love Is Unrequited: Swoons over a boy named Sean, but he doesn't even know she exists. A more noteable example, maybe, is in "What's Love Got to do With It?" where she falls for her substitute teacher, of course, there's absolutely no hope for her, and the episode ends with her in tears.
Dreadful Musician: Angelica thinks she can sing, but to the others, she's horrible. In later seasons, however, she shows some improvement; in 'Interview with a Campfire' she, along with most of the other characters, participates in a musical, and even if not the best singer, doesn't do it too bad either; also, when she manages to participate in a talents show without Susie entering it, she wins first place. Remarkably, it seems she sings her best when doing it as part of a chorus or group rather than when doing a solo.
Green-Eyed Monster: Wants nothing more than to upstage Susie, and will pull every trick in the book to do so.
Evil Virtues : Much of her Character Development comes from her learning how to use her flaws in more positive ways, especially The Trickster and Determinator aspects of her personality. Many times Susie, who's usually The Ace in this duo, is shown to be impressed at her achievements, especially with things Susie had actually failed to accomplish (like defeating Debate champions, kids so smart that actually intimidate her) or does it in a much lower level, as it happened when Susie asked Angelica to help her with a charity collect; working at the same area and time, Susie collects less than a hundred dollars while Angelica, by using persuasion and guilt-tripping, gets over six hundred dollars in cash and a certified check.
Hypocritical Heartwarming : She might offend, tease, and overall antagonize her cousins and friends on a regular basis, but she'll get fiercely defensive of them if anyone else does it.
Remarkably, she often gets Chuckie's help for her projects and plans but, unlike the original series, when she just forced him to help via intimidation, here they become more-or-less equal partners, with both of them gaining something from the bargain, and in fact when one seeks the other's help, he or she usually offers a Pro Bono Barter. Even if it's often a Leonine Contract on Angelica's side, she always sticks to her part of the deal and at times she actually accepts to help him without asking for any (on screen) reward.
Pet the Dog: Her attachment to a baby ostrich in "Dude, Where's My Horse?"
The Shrink: Runs an advice column, and is a borderline Type 1.
Vitriolic Best Buds: With Susie. On the one hand, she's incredibly resentful towards Susie's talent and they're often at odds. On the other hand, she does care... deep down... and is clearly a lot closer to her than to the popular kids, with which her relationship is knowingly superficial. When at one point Susie risks her life, Angelica does the same to try to save her.
Ambiguous Disorder: Sometimes, characters think that there's something severely wrong with him just by how he acts. However, when Didi was told this, she was nottoo happy.
Chaste Hero: Given his young age compared to the others, he's probably the only character on the show that doesn't really fall for anybody.
Childhood Brain Damage: It's mentioned that Dil is so strange because Phil and Lil dropped him on his head when they were babies. In another episode, Grandpa Lou claims he was hit in the head by a fly ball at a baseball game. Although Didi doesn't think this is the case, and believes it to be genetic (from Stu's side of the family). Given what Stu and his family members are like, this might not be too unlikely.
First Contact: Dil eagerly looks forward to this. And apparently succeeds in one episode.
Gadgeteer Genius: Just like his old man. Played straight in one episode where Tommy treats him as the go-to guy for creative inventions, which unfortunately begins to rob Dil of his creativity and oddness.
Heterosexual Life-Partners: He's attached to his brother Tommy, and even has a secret handshake with him. He even attempts this with Phil during a falling out with Tommy, but it doesn't work out.
Intergenerational Friendship: Dil is pretty certain this is the case with Pangborn since the start of the series. Pangborn tends to humor him at first (when he's not outright irritated by him, of course), but the trope is played straight over time.
Disappeared Dad: Inverted. She knows where her birth dad is and keeps in touch with him, but is a continent apart from him due to her mom re-marrying Chaz. He even visits her in one episode.
Easily Forgiven: Despite the many times Kimi put her own overzealous interests over everyone else and gets way in over her head, people apparently let her off the hook, especially Chuckie. Meanwhile Kimi acts as if nothing major happened. Unfortunately, the same cannot be said for Tommy (or Angelica when she least deserves it).
Far East: The chopsticks in her hair in Season 1, her focus on her Japanese heritage in Season 2 onwards.
Freaky Fashion, Mild Mind: Kimi's fashion on the show tends to lend to a 'bad girl' image, but she's still nice overall. This trope is only really hammered home when she shows up to work with a mohawk.
Lethal Chef: Starts off as this in "Dude, Where's My Horse?" She gets better. Lampshaded by Lil, who describes her egg rolls as "prone to explode."
Little Miss Snarker: As opposed to the sweet cheery girl people may remember from the original series (with the exception of the comic strip), Kimi is a general snarker towards any one close to her, possibly due to being old enough to recognize gender differences, her lack of sympathetic nature, and generally seeing boys her age as immature.
Red Oni: Kimi is quick to anger, impatient at times, often easily standoffish (as well as often being the most bluntly snarky of the group, which is saying something), often instantly passionate about things and has a strong enough sense of justice that she will almost immediately rally behind a cause with lots of fervor. Interestingly, her Blue Oni is her own mother, who is exceedingly calm, patient and level-headed. However, as Kira is only rarely a major character Kimi is more often a Foil for Chuckie.
The Ace: She gets all of the good grades, she's a talented singer, and she's basically loved and respected by her peers. Deconstructed Trope in 'Susie Goes Bad Lite', as she reveals that keeping this image can be quite stressful at times.
Badbutt: Her attempt to avert her "goody two-shoes" status in the aptly named "Suse Goes Bad Lite". It doesn't work out.
Broken Bird: Almost became this when she got conned out of a thousand dollars.
Cool Big Sis: Plays this role towards the others, though less as much than the original show.
Vitriolic Best Buds: With Angelica. One the one hand, whenever Angelica's got some scheme going Susie's the first to try and take her down, sometimes going out of her way to stick it to her. On the other hand, she's probably the best friend Angelica has and often tries to do what's right by her (and encourage her to do the right thing)... even if Angelica doesn't see it that way. A lot of episodes involving Angelica and the popular kids also have Susie being the more supportive friend.
Geek : Loves action figures and comic books; in 'Superhero Worship' he goes to a comic-con and cosplays as his favorite superhero, almost getting into a physical fight with fellow geek Chuckie as they defend their favorite superheroes, and in the end of the episode he continues using the disguise on the street.
Genius Ditz : Despite being quite klutzy, he has some useful or cool abilities, including skating, guitar playing, baking, and manual work in general; remarkably, he once broke a DNA model Susie needed a week to complete, and replaced it with a far superior one he did in just one afternoon... while claiming he was lucky enough to 'find the hiccups gene'.
He's also very competent at giving sensitive, reasonable advice (except when Rule of Fun is on play), and only stops doing it because he has problems handling the pressure of hearing so many problems at once.
Satellite Character: By simply being Tommy's girlfriend and having a limited number of appearances, she never hangs out with Tommy when he is with his friends, nor does she have interaction with anyone else, aside from Didi in "Lost at Sea".
Jerkass: Boy, does it show in "The Old and the Restless". He constantly puts down Grandpa Lou during the tour and doesn't even lift a finger to help Tommy and Justin escape from a malfunctioning exhibit, because in his own words, he's "too cool for that."
It gets somewhat better in Season 2 onwards, explained in "Interview With a Campfire" as the result of a few touch ups.
Shout-Out: Her disco outfit in the pilot is one to Madonna.
Demoted to Extra: In Rugrats, he was one of the most prominent adults on the show, but here he's barely seen and doesn't even talk save for a few episodes. It's particularly noticeable when you realize that Michael Bell also voices Chaz, who appeared often.
Averted in "Brothers Grimm", where he plays a major role in the episode with Stu.
In 'River Rats', Phil also mentions a Noodle Incident when Betty saved a bus full of children, and literally did it single-handely since she had a fractured arm at that time; not to mention she was holding a pizza while doing the rescue.
Cloud Cuckoo Lander: Sometimes. Who else do you know would cheer loudly when they DIDN'T win a raffle?
Real Men Wear Pink: In his spare time, writes poems that tastes like diabetes, and in one instance, went 'Oopsie!' when he was just about to step on a ladybug. And can still put you in a neckbrace if you tick him off enough.
Shout-Out: Seems to be one of Jesse Ventura, another bald wrestler who took up a professional occupation.
You Remind Me of X : The 'Remind me of Myself' variant. The reason Chuckie is such a fan of Armadillo Dave is because they're too similar, and AD manages to be a hero despite all his flaws, something Chuckie longs to be.