Various Keronians who appeared up to the anime's 5th season
|Wordplay name||KeroKero (Ribbit)|
Keronians (ケロン人 Keronjin) are the inhabitants of Planet Keron. Keronians are known as an invader race. In spite of that, there are many different kinds of Keronians in the anime and manga.
In their initial growing phase, sometimes identified as tadpoles, Keronians already resemble semi-anthropomorphic frogs more than they do actual tadpoles. They are mostly differentiated by a short tail with a flat, disk-like fin and a white coloring on their faces. However, some like Gyororo might have different coloring for the usually white area on their bodies.
Most adult Keronians lose their tails and the white of their face recedes from between their eyes down to the the top of their mouth. Some Keronians, like Pururu and Tamama, retain their tadpole appearance for longer than usual. In general, considering various female Keronians in both the actual series and additional material like Keroro Land characters, females seem to keep their youthful appearance for longer than male Keronians. Early in the manga, in an extra fourth wall breaking page, Tamama describes his appearance and tail as a genetic peculiarity rather than a sign of youth. However, later in the manga's actual story, it was referenced that the Keroro platoon underwent an anti-aging treatment, which could explain Tamama's situation. Shin Keroro has a tail without the white thin, which is described as a mutation..
Keronians generally wear headgear as their only item of clothing, but there are some exceptions. The Keronian headgear most commonly seen resembles an army helmet with attached ear flaps. This style comes in many colors and is not standardized to yellow. Some female Keronians have 'horns' or 'bumps' on their headgear. All Keronians have an emblem, which most of them wear their headgear and belly, but some do not wear the latter. (Ex: Giroro). It should be noted that the emblems are a created as a pin for the hat and a sticker for the stomach; they are not born with the emblem.
Keronians are also often portrayed as growing hair, although mostly for comedic purposes; Keroro mentions cutting one of his eyebrows to punish himself while training . Older Keronians, like Keroro's Father and Keroro's Mother also are often portrayed with hair, like Keroro's Father's mustache and his mother's afro. In episode 234-b when the platoon used the time machine to fast forward 10 years, Giroro and Tamama are seen with white mustaches and Keroro is seen with a full white beard; Giroro's father has large bushy eyebrows and a mustache.
In episode 316 when Momoka switched bodies with Keroro, she accidentally takes off his hat and is surprised in a bad way by what is under it. She also adds that it's probably the same for Tamama.
Keronians not only resemble terrestrial frogs but share multiple weaknesses with them. They like humid areas and they dry up when it's too hot or dry. They are also weakened by cold temperatures. If it gets too cold, a Keronian will go into hibernation, though they do possess some powered suits that can mitigate the effects of weather that's too hot, dry or cold for them.
When a Keronian absorbs too much humidity, they become prey for the nyororo. It also appears to give them more energy and vigor, however, this effects varies in intensity for each one. Keroro is highly influenced by the weather, becoming hyperactive and aggressive once the humidity is high enough.
They can also naturally swim very well and fast - surpassing speeds possible for humans in spite of their smaller size. However, they're unable to breath if their skin is covered by salty water, which also dries up their body.
They have human-like teeth. Unlike humans with permanent teeth, their teeth can grow back multiple times if damaged or destroyed.
At least in the anime, they also have a high resistance to blunt impact, even cushioning their human friends during falls.
Keronians are considered an "advanced" species and this doesn't involve only technology. They have training techniques that allow them to manipulate energy to achieve various special powers. In fact, it's remarked that using eye beams is common knowledge to the point that it's considered kind of lame.. The Keron Army's Assassin Unit is a combat unit specialized in controlling such special techniques, utilizing Assassin Magic.
Dororo was surprised to learn that, although not widespread, some humans on Earth, like ninja, were able to use similar abilities. In the same way though, he quickly was able to incorporate Earth ninja techniques in his arsenal.
Keronians can also stretch their arms up to as long as their body, something done commonly by practitioners of cosmic aerobics.
The symbol on their hat works as a universal language translator, an environmental regulator, and an Anti-barrier that makes them invisible. While the Anti-barrier is confirmed to be battery operated, the other two functions never seem to fail even when the Anti-barrier runs out of power.
There are also mutant Keronians with special abilities derived from that, like Darere. In Darere's case, he has the ability to mimic the appearance and voice of other living beings due to his mutation (including being able to mimic humans and similar sized aliens).
- The Hinata Family, the Momoka Residence, the Kissho Academy Newspaper Club, Sabaro, Omiyo, Koyuki, Kana and Santa Claus are the only Pekoponians that know of the Keronian's existance.
- All of them (Up to Movie 3) that were in the anime was shown in Our Password.
- A lot of Keronians have Pekoponian partners.(See the page Partners)
- In Episode 27, when Fuyuki speculates that Keronians are born by cloning, in his imagination Keroro is shown growing with his hat like it were a part of his body. He also imagined an actual tadpole stage for the Keronians.