In the Abridged series, Keroro is a useless, self-absorbed Jerk Ass who can't accomplish anything (big shocker, right?). He occasionally makes an effort to come up with an invasion plan, but sadly his plans wouldn't make sense to a two-year old. Has a fear of being useful, is in a relationship with subordinate Tamama, and is apparently Hispanic. The entire series revolves around his friends and peers wanting to kill him because they hate him so much. Voiced by Mugiwara Yoshi.
Ambiguously Gay: Averted in the early episodes. As soon as he makes a pass at Tamama when the character is introduced, he outright says "I'm gay! The end!". Also inverted, because he seems to have an attraction to women but won't come forward about it like he will his attraction to Tamama. Subverted by Episode 11, where he comes to grips with his sexuality and decides he is Bi. Doesn't stop his relationship with Tamama from getting any worse.
Tamama is Keroro's adorable boyfriend until he is revealed to be a "she" at the end of Season 1. Tends to act stupid like the rest of the platoon, but occasionally exhibits rational thought. Voiced by ThornBrain.
Ambiguously Gay: Averted. One of his nicknames is "fagmuffin". Becomes subverted when he ends up being straight only because he is a "she".
Ambiguous Gender: Both in- and out-of-universe. Even Tamama herself didn't know she was a girl.
Static Character: Despite showing moments of Hidden Depths throughout the series, Tamama never changes much beyond this characterization. Writer Travis admits that he would like to develop Tamama's character more beyond this. Her appearances in Ask GiroDoro SFA made the effort to emphasize her sarcastic side and her tenuous relationship with Keroro.
Unsettling Gender-Reveal: Tamama turns out to be female, much to the surprise of everyone, including herself. This sent Keroro into 'straight panic' in episode 11.
Giroro is Keroro and Dororo's lifelong friend, though he is less than pleased with Keroro's failures and would like their platoon to successfully invade Earth. Had a transparent crush on Natsumi until getting together with and eventually marrying Dororo, and is a transvestite. After the wedding, Giroro no longer wants to invade Earth, and instead just wants to live a peaceful life. Voiced by ThornBrain.
Can Not Spit It Out: Averted. He outright says he loves Natsumi in Episode 5; nobody seems to notice or care, not even Natsumi.
Jerk with a Heart of Gold: He acted sweet towards Natsumi and developed his friendship with Dororo much more than with any of the others. By the end of Season 2 he clearly cares about his friends and protecting them.
After being stranded in the forest with a broken leg, the lonely, depressed, mentally damaged, socially awkward, unpopular rich kid Dororo became a ninja. He appears to have a form of Stockholm Syndrome in relation to Keroro and Giroro, but his only true friends may indeed by Giroro and Koyuki; nobody else seems to care about him. By Season 2, heaps of Character Development has led him to not take Keroro's crap so much anymore and settle into a happy relationship with Giroro. Voiced by ThornBrain.
Breakout Character: Even Yoshi didn't care about him until they finally introduced him. He almost immediately became a fan and creator favourite, and he was voted Travis, Yoshi and Thorn's favourite and best-developed character at the end of the second season.
Ill Boy: Taken to a ridiculous extreme come Episode 11. According to Pururu, Dororo has every virus, germ, parasite, cancer, and other diseases in his body, some of which are female-exclusive. They're all dormant, completely benign, and non-contagious. The kicker? He got them all because he wanted to make friends.
Of course, come the next few episodes, it's pretty clear they're not fully dormant or non-contagious.
Dororo releases his diseases into the wilderness like wild animals in the series finale. It is unknown if he does the same following Reset.
Malicious Misnaming: The longest running gag of the series. Characters often switch his name with something starting with D (Doorknob, Dorito) or something completely random (Laryngitis, Hangnail).
Momma's Boy: Suggested in flashback episodes of Season 1 but subverted in Episode 10, where he reveals resentment towards his mother. He is very uneasy about seeing her again in Episode 19.
Oblivious to Love: Koyuki sees him as a good friend, but for the most part he seems oblivious and just wants his platoon to be his friends (which he actually did accomplish with Giroro; then they kept going).
The biggest personality reversal from the original Keroro Gunsou. Kululu isn't the transparently scheming, constantly-giggling Token Evil Teammate like his counterpart, but is rather an understated, keeps-to-himself, sarcastic, apathetic Jerk Ass. Voiced by Jpace92.
Start of Darkness: The team was in fear of this due to Future Kululu wanting to kill them all, which is taken seriously in Episode 12. He actually seems pretty mellow about the team.
Token Evil Teammate: Subverted. Throughout the first season he's about as blatant as his main series counterpart. However it was mostly his future doppelganger. The real Kululu returns at the beginning of Season 2, and he mellows out considerably.
Troll: He once trolled a leading economic power and the leaders of the world at once, and collapsed all of Uganda with porn.
Un Evil Laugh: Has switched out to the much less menacing, much more nasally "HEGH!"
Mois is a sweet alien girl with a big crush on her longtime family friend Keroro. As opposed to the original Mois, this character accomplished her mission to destroy the world. Voiced by codeblackhayate.
Took a Level in Jerkass: Towards the end of Episode 13, after Mokoma's death by head explosion, he makes several puns at her expense.
The girl of the house who is less than amused by the Keronians. She is the center of attention at her school by all of the females, and she wishes she could just have a friend instead of an admirer. Voiced by LillyLivers.
Revolving Door Casting: She was voiced in Episode 2R by LillyLivers as a backup, following many failed attempts to find and hold down a voice actor for her before she ever debuted. This trope is the reason she was removed from most of Season 1 out of spite.
Natsumi's secret crush. He has a radio show, despite being mute, or at least unable to say a single word without being interrupted.
Butt Monkey: Every time he opens his mouth to talk, someone else starts talking. Even Natsumi, the girl with a crush on him, failed to notice him in Episode 1, leaving him sad and crying. His lack of respect is comparable to the original Dororo's role.
New Powers as the Plot Demands: His magic pen was never addressed in the series, and he doesn't speak so he can't explain anything. Thus comes Episode 17 when he rescues the Hinatas with a drawing of a shield, and Episode 20 when he suddenly gains explosive powers and incendiary spraypaint.
Suddenly Voiced: Albeit briefly, by fellow voice-based running gag MrFailGame in the series finale.
Other Recurring Characters
Writer ThornBrain occasionally acts as the disembodied voice that details the setting of a scene and makes sarcastic remarks. His role as narrator is considerably smaller than the Sgt. Frog counterpart, and he rarely shows up after Season 1.
A childhood friend of Keroro, Giroro and Dororo with something of a loony streak. Arrives out of nowhere to give the platoon checkups, which is just a cover for her to find out the platoon's weaknesses. Voiced by LillyLivers.
A Degree in Useless: Word of God says she got her medical degree in the Keron equivalent of Coney Island, which her voice actor LillyLivers describes as the "most backwards fucking place in the world". Her completely wrong diagnoses of the platoon confirm that in-universe.
Cloud Cuckoolander: Most obvious as a kid. She seems fairly focused as an adult, but still has moments where her warped mind is noticeable.
Cute and Psycho: Attractive and pleasant; secretly harvesting organs for cash.
Distaff Counterpart: To Keroro in many ways, including having a casual approach to sex and sexuality, being pretty rubbish at her job, and having her own "Serious Pururu" moment (as in "I'm so serious, even the jokes I tell are serious" Pururu).
The Mole: She's really there to learn the platoon's weaknesses and relay them to Garuru.
Sticky Fingers: She reveals in her Season 2 finale reappearance that she's been pickpocketing the time-locked populace and shoplifting stores. In the audio blog, Giroro and Dororo reveal that she also stole a house.
The main character of the Metal Gear games makes recurring cameos to reference said series. He mostly appeared as a recurring One-Liner gag, but became an actual in-universe entity in Episode 7. Voiced by ThornBrain.
Ascended Extra: He was originally just a random gag, but he became an actual character in Episode 7.
Duel to the Death: With Raiden in the Season 2 finale. According to the credits, both lost. They're both back to life in Reset.
The fellow main character of the Metal Gear games has also started appearing in Season 2. He does not reference MGS so much as act like a walking metrosexual Facebook/Twitter feed. Voiced by BigTUnit1.
Viper is a half-snake, half-humanoid space pirate with an apparent history with the Keroro Platoon, (he's Dororo's dad). After capturing Dororo and Koyuki in Episode 4, he is relegated to an occasional cameo, usually voice-only. Voiced by BigTUnit1.
Then subverted, as Dororo isn't sure if Viper is his biological father when he grows up. Double subverted by the end of the second season where, despite the father debate never being settled, Dororo is at least well-adjusted enough to not be burdened by the issue any longer. As such, Viper is simply accepted as his father.
Tangled Family Tree: It seems straightforward at first: Viper, his father, his wife, their kids. But then in Episode 19 we meet his "Mom-Son" and "Dad-Train"...
Kululu's future self. He is apparently the Kululu seen from Episode 6 through Episode 10, and the present-day Kululu is trapped somewhere in the meantime. Kululu turns into him at the end of Season 2, then back to normal in Reset. Also voiced by Jpace92.
Evil Laughter: He alternates between the "HEGH" laugh and an actual evil cackle.
Knight Templar: He's trying to kill Keroro so that the mission to invade Earth actually gets accomplished.
An unnamed Admiral in the Keron Army with a lethal loathing of the Keroro Platoon. He dumps the platoon on Earth to get rid of them, only to send people and weapons after them to kill them. Generally speaks in a bored monotone. Voiced by TheSmashBro.
Dull Surprise: His usual speaking voice. You get the sense that he's not crazy about his job.
Jerkass: He dumped the platoon on Earth with the implication that he just wanted them out of the way. He never made clear that they still had an invasion mission, and now he's trying to kill them for wasting time doing nothing.
The Voice: Never seen; only heard over intercoms, answering machines, or while having a monologue to a black screen.
The ridiculously friendly, yet surprisingly dangerous, commanding officer of the Garuru Platoon and the older brother of Giroro. He is under the illusion that Keroro is a military genius when he's really a complete idiot, and thus anything Keroro does is mistaken for a brilliant strategy. He and his platoon are sent to Earth to finish off the Keroro Platoon in the event that the Kiruru from Episode 16 did not kill them all. Voiced by BigTUnit1.
Affably Evil: Up to Eleven. He's so nice, it drives Giroro insane. Ultimately subverted: he was overly polite in regards to Giroro because he didn't want to make his brother feel bad about all of his faults.
So Proud of You: To Giroro, but mostly for mundane things from years back such as teaching him how to read. He is also aware that Giroro is a failed soldier, but he is convinced that his brother has survived thus far because of whatever skills he learned anyway. Reset also shows that, despite his niceness being exaggerated for the sake of Giroro's self esteem, his pride in Giroro is completely genuine.
Villainous Breakdown: He mistakes everything Keroro does as a genius maneuver, causing him to have a few mental battles with himself over it (and lose). By the end he finally snaps and just orders his platoon to attack.
Worthy Opponent: To Giroro. Seems to think Keroro is this when he's really a complete idiot.
Lance Corporal Zoruru
The Garuru Platoon's half-cyborg assassin who kills by using a blade hidden in his robotic arm and speaks in a sneering whisper through a speaker. Being the cold-blooded opposite of Dororo, he is convinced that everyone wants to be his friend and that no one will leave him alone. He has heard rumours that Dororo is indestructible and wishes to prove them wrong. Voiced by ThornBrain
Defeat Equals Friendship: Played with. He never fights Dororo, but Dororo mistaking him for Robocop is enough to convince Zoruru that someone out there doesn't know about him. He leaves very happy, and as with Garuru, it is implied that he is on good terms with the Keroro Platoon afterward.
Evil Counterpart: To Dororo, even in personality: where Dororo used to feel lonely despite often being with friends, Zoruru is paranoid that people won't leave him alone and all want to befriend him, despite him usually working alone.
Evil Laugh: Gives a low, quiet one before killing Saburo.
Harmless Villain: His introduction marks the first aversion of this trope in the series.
Harmless Villain: The only reason he defeated Tamama was because Tamama defeated herself, and she redirects that power properly the next time they meet. The one time he does an attack, he apparently hurts himself.
The hyperactive techie of the Garuru Platoon, Kululu's son, and a big fan of Mint's Hints. He spends his time hacking Kululu's system and laughing maniacally for no reason. Voiced by BigTUnit1.
Leader and namesake of the Shurara Corps, and yet another person with a big grudge on Keroro. He has a flair for drama, a very literal mind, and he can be quite mean to his own Corps. Voiced by ThornBrain.