The Chew Toy: Ukraine and the Baltic States — Latvia and Lithuania in particular.
Truth in Television applies for this one, particularly if you toss Poland into the mix as these countries have been the traditional Chew Toy of Europe and have been frequently invaded and conquered. Most of these countries have spent more time under the foot of the more powerful countries for the last millennium.
Word of God says he purposely averted this with Poland, because while Poland has the image of the poor country stuck between Germany and Russia, it kept on rising back, like a phoenix.
Flower Motifs: Russia is sometimes seen with sunflowers. In one strip, Russia tells Lithuania that he dreams of "living in a warm place surrounded by sunflowers". They put the "dere" in Yandere for him.
Latvia attacks Sealand with a Lily of the Valley at one point (which is, interestingly, Finland's national flower), the first hint of his Yandere or Cute and Psycho potential.
Rye fields. Just... dear God, the rye fields.
Hair Decorations: Both Ukraine and Belarus use hairbands. Ukraine also adds some hairpins.
Odd Friendship / Opposites Attract: Poland is cheerful and hyper, Lithuania is gentle and kind. At some point they even were in an alliance, which is pretty much assumed to them having been married. (To be fair, the alliance itself did start with the marriage of their bosses, Duke Jagiello of Lithuania and Queen Jadwiga of Poland)
Pink Girl, Blue Boy: Sort of inverted with Russia and his sisters. Ukraine is recognized for her blue overalls, Belarus is recognized for her indigo/blue dress, and Russia is recognized for his scary purple aura, pink flowery aura, and (sometimes) pink scarf. And then Poland is associated with pink too...
Satellite Character: Eventually subverted with Ukraine and Belarus. Ukraine is the most socially intelligent of her siblings, and is shown interacting with the other female characters and the other Eastern European countries without a mention of her family in the events. Belarus gets a ton of insight on her character beyond her Big Brother Attraction in SeaLat Desktop mascots, and the events. Where they play this straight, however, is in their audio CD, where they are little more than Russia's incestuous fangirls.
Brother Pennybags: Estonia is the rich one of the Baltic states and always happy to help them out. One strip is an advertising pitch for more tourism. He is also described as a Honors Student and 'reeks of money'.
If you don't have friends ... things will...your heart and body will.. it'll be so tough...* sob*
Voiced by: Kazutada Tanaka (JP), Ryan Reynolds (EN)
Adaptation Dye-Job: Generally depicted with light blond hair and violet eyes in the manga, but has dark blond hair and bright blue eyes in the anime. His hair color was changed to a lighter sandy blond in the fifth season, though he kept the blue eyes.
The Alcoholic: According to some notes and the desktop mascots. Despite being too young to drink in human age.
Nervous Wreck: The funny thing is that he actually works better under pressure.
Right in Front of Me: Quoting his profile: "Often lets wrong things slip out in front of Russia and has to face the consequences".
Shrinking Violet: To the extreme. When Russia wonders why Latvia's always twitching when he's around, he grabs Latvia and demands he stop. Latvia does... but goes into a coma and almost dies. Cut to Estonia's horrified screams.
Ever since returning, I've been worked to the point of no sleep... It must be because Russia is pissed off...
Voiced by: Otsu Kou (Flower of Iris CD), Ken Takeuchi (JP), Josh Grelle (EN)
Adaptation Dye-Job: His hair is much lighter colored in the anime and his eyes were blue for the first four seasons. His color scheme was changed in the fifth season to be closer to the manga, where his eyes are green.
Finland: He's usually so kind, but in battle his aura and face change.
Diving Save: In the Battle of Tannenburg, Lithuania saves Poland just as Prussia is about to bring a sword down on his head, as well as having a knife against Prussia's throat. Poland lampshades the trope when he remarks on how Lithuania was "totally late".
Dogged Nice Guy: To Belarus, even when she hates him and makes it very clear.
Dude Looks Like a Lady: Not as much as Poland, but his long-ish hair, big rounded eyes and slender figure can put some off, and his docile personality doesn't help. On the character identification chart, he's put in the "unknown gender" section.
A scanlated strip has a dream sequence in which a younger Lithuania tells Poland that he hates him for being so selfish. Poland's response? "I, like, totally don't care what [Lithuania] thinks of me. Even if you, like, hate me, it totally doesn't change that I like you." Then he says that he'll try to be less selfish. The expression he uses in Japanese can also just as easily mean 'love'.
In-Series Nickname: Poland calls Lithuania "Liet"; it comes from Lietuvos, the endonym for Lithuania.
The Right Stuff translation of Vol. 3 has Poland call him "Lithy" instead.
Love Martyr: Lithuania's one-sided crush on Belarus certainly comes off as this trope. He constantly overlooks her violent tendencies... hell, he was perfectly okay with her breaking all of his fingers.
Actually he just didn't notice, and Belarus' violent tendencies either, it's made apparent that he didn't realize the condition his fingers were in til Poland pointed it out and even then he just assumed that his fingers could bend that way while Belarus broke his remaining non-fractured fingers.
Not so Above It All: Sure, most of the time Lithuania is portrayed as a genuine Nice Guy amongst the insanity of Russia and Poland, but he does occasionally express frustration, particularly with Poland.
Telling Prussia he hates him and giving him the advice of "Russia loves people who laugh and cry easily" was certainly not nice. Said scene also implies that yes, Russia's occupation had pushed him to his limits.
To wit: You know you're wimpified when you're regularly shown being topped by a crossdresser that loves ponies and talks like a Valley Girl.
Yank the Dog's Chain: He never seems to get what he wants. Because of Russia, Poland and Lithuania are split apart. For a while, Lithuania works for America and much prefers that life, but the Great Depression hits and he has to go back to working for Russia. When he finally gets a date with his crush Belarus, she breaks his fingers.
Poland - Feliks Łukasiewicz
Do you think our wheat would sell more if we dyed it, like, blue?
Voiced by: Tohru Ogawa (promotional Hetalia clips), Kazutada Tanaka (JP), Ryan Bijan (EN, Hetalia: Axis Powers), Joel McDonald (EN Hetalia: World Series)
Attention Deficit... Ooh, Shiny!: In Hetaween 2011, he tried to bring a horse to the party, and then spends the entire time sitting on a toy horse, running after butterflies, looking at flowers and being generally distracted before falling asleep, still on his toy horse.
Cultural Posturing: Poland used to treat Lithuania like his lackey and tried to make Liet live like him. Without any bad intentions, yeah, but still not the best thing.
The Determinator: Hinted at being one in his character profile: no matter how much he gets beaten up, he keeps rising back "like a phoenix". Plus, it's accurate.
Platonic Life Partners: Kinda hinted to be this with Hungary, which is supported by the historical connections between both nations. She refers to him as "Po-chan", to start.
Shrinking Violet: Variation. He seems to be outgoing and cheery when around people he's close to, but when confronted with someone he doesn't know, he sometimes backs off and clings to or hides behind the nearest person.
Spell My Name with an S: His name is spelled as Feliks than the more known spelling Felix. Justified since the letter "x" doesn't exist in the Polish alphabet.
Wimpification: Fanfic frequently does this to him due to his crossdressing tendencies. Or, in other words, when Liet isn't made into an uke Fragile Flower, it's because Poland has fallen victim to it instead.
Abhorrent Admirer: Oh, Russia. Of course, he acknowledges that his little sister is a very pretty girl - it's just her Knife Nut tendencies that make her abhorrent...and of course the fact she's in love with her own brother.
Action Girl: Come on, she is almost always seen dual-wielding that knife of her and is one of the most "active" girls. She may cross or be pretty close to cross the border into Dark Action Girl, due to her attitude.
Adaptation Dye-Job: She is best known for being a platinum blonde in the manga illustrations and assorted merchandise, though the anime gives her dark blonde hair. In Season Five, it appears to be back to the light blond.
Hidden Depths: The desktop mascots and autor notes actually give quite the insight in Belarus's tastes and thoughts. Among many other things, she: is good at gymnastics and fortune telling, likes reading the Pravda newspaper, can see ghosts, tends to space out (like staring at the TV's white noise for hours), is a fan of Dmitri Smirnov, and is extremely pessimistic. (Apparently, due to Belarussian history as a whole)
Hot-Blooded: When it comes to Russia. Or someone competing against Russia.
Subliminal Seduction: Subverted in that she seems to be trying this during the 2011 Bloodbath by watching Lithuania sleep with a Battle Aura around her, telling him to revere Russia. Oddly enough, it seems to work in that he has a dream about him.
Super Strength: Although this is hinted to be a trait of several nations, let us not forget that she clawed through a door and removed its knob with her bare hands in her introduction.
Belarus: Dear brother... Why will you not give your signature to our marriage papers? Have you already chosen another one to give your signature to? ...YOU! IT'S YOU! THIS WAS YOUR DOING! UNFORGIVABLE! UNFORGIVABLE! UNFORGIVABLE!
Ukraine: I'm sorry for being such a bewitching older sister...
What Could Have Been: According to this blog entry, Belarus originally was supposed to be a brunette and quite more mellow and stable. A remnant of this idea can be seen in her first colored manga appearance, where her facial expression when threatening Latvia is a little less severe, while her hair and eyes are both colored brown.
Volume 3 notes also revealed that Himaruya played around with the idea of a Tsundere Belarus who was hot-tempered and constantly nagging.
When She Smiles: In the latest Christmas series, one of Finland's tasks is to get a shot of Belarus smiling. Once convinced that Russia is watching the show, she gives us this◊ (before assaulting Finland). Wow.
She also gives a very small, almost unnoticeable smirk at the end of the 2011 Halloween Event that is also very adorable.
Yandere: She is obsessed with her older brother, is often represented with a knife, and shares Russia's penchant of abusing people who show care for her - especially Lithuania... Heck, Belarus is so Yanderiffic that Russia is scared of her!
Adaptation Dye-Job: Some manga illustrations show her with a darker, more yellowy blond hair color while the anime gives her platinum blond. Season Five of the anime later changed it to the manga's colors.
Badass Longcoat: Her military uniform includes a jacket that goes past her knees.
Brother-Sister Incest: It's implied in her and Belarus' song that she has feelings for Russia too, even though Belarus is far more upfront about it.
Bizarrely, her introduction in the manga showed that while she still has affection for him, she clearly does not want to be in a union with Russia again. In fact, on the relationship chart, her feelings towards Russia were "I want to leave right away!" and Russia wondering why she "hates" him (in contrast with Belarus's "let's marry!")
Fan Nickname: To make up for her lack of a proper "human name" fans call her Yekaterina "Katyusha" Braginskaya, her surname being the female variant of Russia's last name (Braginsky) and Yekaterina (Catherine/Katherine) being a common enough name for Slavic females.
Huge Schoolgirl: While Ukraine does not have an official height, the difference between her and her sister makes her appear to be approximately 168cm (5'6"-5'7"), which is taller than average for a woman. It's not uncommon to see her drawn as the tallest female in the series in fanart.
Russia: "I don't think it's really going to work for me..."
Innocent Fanservice Girl: Often gets this in fanworks, although it's played with in canon; her bust is much larger than the other girls' and is prone to Gainaxing, but played for laughs. Despite this, she usually dresses modestly (even constantly trying to repair buttons on her shirt rather than just leave it open a little bit), is aware of her chest, and politely turns down Hungary's teasing to wear a dress that would completely expose her breasts.
Satellite Character: Subverted. a first it seemed that a good part of her character was centered on her brother Russia... but then we have her her interactions with the other girls in the volume four bonus and the 2011 Christmas Event, in which she is motherly and supportive towards them and doesn't bring up her siblings once.
Team Mom: Ukraine was this for Belarus and Russia when they were children; she gave Russia a scarf once when he was cold, and he still wears it as his trademark. She's also said to be the one who fixes her siblings' Yandere screw-ups, and is among the few nation-tans that Russia shows his almost nonexistent deredere side to.
Russia (on Ukraine): "She has a big heart and is often targeted because of it. She's a bit of a crybaby too."
Also takes care of Poland in the Halloween Event, so it may be implied that she is also this to the rest of the Eastern Block nations.
Our Vampires Are Different: Some people suspect he may be a vampire, since he has red eyes and is the home of Dracula. We have yet to see whether or not this is true, although the Cute Little Fang he sports might be hinting at that...