Nekotalia

Nekotalia originates from a strip in Hetalia Volume 3 and several images and webcomic strips by Hidekaz Himaruya in which the nations have cats which share similar personalities and features to them. Some of these cats are owned by the nations they represent, however they all are referred to with "cat" following their nation's name, seemingly to have them represent the nation as well. The term Nekotalia derives from neko, the Japanese word for "cat" and talia, from Hetalia, the name of the base series. They are somewhat comparable to Mochi in the series.

America Cat
America Cat is a large white cat (though he appears to be yellowish in the anime) with a thin semi-circles beneath his eyes drawn to represent America's glasses, and long, dark fur around his neck, resembling the top of America's bomber jacket. When Finland was asked to take pictures of the Allied Forces cats, he described them as being free and uncontrolled, saying they were "next to impossible" to get pictures of, though America Cat appeared to be inside of a house with a ball about as big as he was, indicating that he might live with America. In his initial appearance in The Summary Up Until Now, he was drawn with an cowlick, leading the beginning of the "World Cat Conference" and meowing a lot.

Austria Cat
Austria Cat is a dark colored cat (alternatively colored purplish and blueish in his colored illustrations thus far) with a white face and white paws. In the manga, the tip of his tail is also white. His fur appears to be somewhat long, especially at his chest and the back of his head. Like Austria, he has an cowlick and a dark spot on his face like Austria's mole. He also wears an Austrian flag ribbon. According to Germany Cat, they look like they act similar, however, Austria Cat is easygoing and they're not like one another at all. According to him, he could not be seen in public after just having woken up due to his breed, suggesting he may be (or believes himself to be or carries himself as though he is) a purebred cat. Nonetheless, he didn't seem to have a problem with Germany Cat seeing him that way.

He appears to be an outdoor cat, as he expressed his desire to be a house cat because he doesn't want his paw pads getting dirty.

Belarus Cat
Belarus Cat wears a ribbon atop her head. She appeared in the bottom corner of the strip in which Russia Cat went to befriend the Italy Cats, staring at them with wide eyes, presumably in an aggressive manner.

China Cat
China Cat is a dark-furred cat with long fur toward his head held back in a ponytail similar to China's, or at least noticeably separate from the rest of his fur, often hanging down over his back. When Finland was asked to take pictures of the Allied Forces cats, he described them as being free and uncontrolled, saying they were "next to impossible" to get pictures of. However, it is unclear if he was on a carpeted floor or outside, in grass. In A Summary Up Until Now, he appeared to be depicted eating a dim sum dumpling. When Japan Cat began his rant against the ban of canned tuna, he agreed with his points.

As opposed to China's "aru", he appears to end his sentences with "arunyan."

Denmark Cat
Denmark Cat is a white long-haired cat with dark gold patches on the top of most of his tail, presumably around his entire middle from behind his front legs to about his haunches, atop his head unevenly, covering his left ear and much of that side of his head, but not appearing to be so full on the right, and under his head on the right side. The fur at the top of his head resembles a lion's mane or Denmark's hair. He appears to have somewhat prominent eyebrows and wears a Danish flag ribbon around his neck.

England Cat
England Cat appears to be a Scottish Fold due to his bent ears. He is a white cat with a large patch of orange fur extending over much of the left side of his face, over his left hind leg or his lower back, and over most of his tail. He keeps the thick lines representing England's eyebrows. He's been depicted as wearing a collar around his neck, showing that he might live with England. When Finland was asked to take pictures of the Allied Forces cats, he described them as being free and uncontrolled, saying they were "next to impossible" to get pictures of, though England Cat appeared to be resting on a pillow, supporting that he may be England's pet. However, he did not appear to have a collar.

His personality appears to be similar to England's as, in The Summary Up Until Now, he was shown disagreeing with America Cat, saying that, if America intended to have a conference, he didn't want to. He meowed a fair amount, his cry rendered as "ma-o."

Finland Cat
Finland Cat is a somewhat fluffy light brown cat with white paws and white at the tip of his tail, as well as at the top of his head. The white fur covers half of his right eve and goes up roundly, before sharply turning down far over his left eye, also in a somewhat round shape, forming a peak-like shape with the brown fur. He also wears a Finnish flag ribbon.

France Cat
France Cat is a long-haired cat with pale fur that looks rather wavy. In the summary of the Hetalia cats, he was drawn with sparkles around him. He's been drawn with a rose in his fur, though it's absent in most images. He apparently has opposable thumbs as he is known to enjoy decorating his room, which is super creepy and why is no one talking about this?! When Finland was asked to take pictures of the Allied Forces cats, he described them as being free and uncontrolled, saying they were "next to impossible" to get pictures of. France Cat, however, was either inside, in front of a window, or outside, in front of a door with windows on it or simply with a window in the background.

His personality appears to be similar to France's as, in The Summary Up Until Now, he mocked the other cats for lacking elegance. His cry was written as "ruruna-o", "le le meoow."

Germany Cat
Germany Cat is a black cat with blue eyes who wears a German flag ribbon around his neck. He is serious, just like Germany, and he even has a strict rule about his naps, lest he be punished, was concerned about being late to the Cat Conference, and hissed at the other cats in A Summary Up Until Now that the meeting that day would go properly. It's possible that he is one of Germany's pets, as Germany was stated to own two cats, the other cat possibly being Prussia Cat. Italy Cat says that their relationship is amusing/interesting, which is why he plays with him even though he's a male cat, though when he disturbed his nap to try and get him to play (waking him up, telling him to stop showing off and play) he greatly upset him, especially when he touched his scrotum while trying to play quietly. However, Germany Cat was quick to forgive him, his forgiving nature being something that Japan Cat liked about him. He intended to return to napping afterwards, asking if Japan would join him as rest was important, however Italy Cat was noisily flirting with a female cat, causing Germany Cat to attack him.

Greece Cat
Greece Cat is a grey and white cat with long fur and a bored expression. There is a notable grey heart shape on his right flank. His front paws are white, however his back paws seem to be grey, as is the rest of him with the exception of his face, back, and half of his tail down to the base.

Hungary Cat
Hungary Cat is a white cat with green eyes, a brownish patch on her right flank, three brownish stripes on her tail with the tip being entirely colored, and brownish patches atop her head forming a smooth, peak-like shape with the white portion of her fur. She wears a flower under her right ear and a collar with a cross on it.

Iceland Cat
Iceland's Cat is noticeably the smallest cat in the image collection, presumably being a kitten. He is small and white with a grey spot over his eye and an Icelandic flag for a ribbon. He is depicted in a basket.

Italy Cat
Italy Cat is a white cat with brown patches of fur on his head, left leg, back, and tail, Italy's closed eyes, and a curl on the left side of his head. He is highly playful and flirts with female cats regularly, though he says that he has fun playing with Germany cat even though he's male, as well. His brother appears to be Romano Cat, whom he doesn't seem to get along with, much to Russia Cat's dismay. However, he appears to consider Germany Cat a friend, though he did bother him and swat at his balls when he wanted to play while Germany Cat was trying to sleep.

In a blog post, when asked about names for the other Nation Cats, Himaruya said that "Italy Cat is Gino." He has the peculiar-sounding cry of "ve-nya," "ve-meow."

Japan Cat
Japan Cat, also referred to as "Tama" by Japan, is the best creation made by Himaruya's cursed mind. He is a black and white cat, presumably a Japanese Bobtail. His fur is black with the exception of his paws, his bobtail, and the space of his muzzle under his eyes and over his mouth, down to the front of his chest, though his tail is black in the manga. He shares Japan's soulless eyes. He loves tuna and stood up against Monaco Cat's ban of it. He becomes quite a "demonicat" (鬼猫, oni neko) when food is concerned. While, usually, he doesn't make much noise, when Japan gave him tuna, he couldn't help but declare how delicious it was, possibly in Japanese, shocking Japan.

Norway Cat
Norway Cat is white with very long fur, some of it held in a ponytail over his left eye, and the same floating curl as Norway. He wears a Norwegian flag ribbon around his neck. It is likely he can see magical creatures as Norway can, as he was drawn looking at a fairy.

Monaco Cat
Monaco Cat is a long haired cat with white fur and blue eyes. On the left side of her head, there's a ribbon tied into her fur. She also has streaks in her fur, representing Monaco's glasses. She wears a jeweled necklace, whose gem is the most part visible through her thick fur. Because the neighborhood's supply of tuna was running low, she suggested a ban, however she was stopped by Japan Cat.

Prussia Cat
Prussia Cat is a white cat with pink eyes and a scar over his right eye and left shoulder. Whether his coloring is meant to be a mark of albinism and whether his scar impairs his eyesight is unclear. Like Germany Cat, he wears a German flag ribbon, though his is torn or ribbed at on the loose ends. It is presumable that, like Germany and Prussia, they are brothers. His fur appears to be somewhat longer or less neat than Germany Cat's.

Romano Cat
Romano Cat is a white cat with the same markings as his brother, simply in orange as opposed to brown, and with his curl coming off of the top of his head as opposed to the left side. He also lacks the closed eyes in most images. He doesn't appear to get along with his brother or Germany Cat, and is scared of Russia Cat.

Russia Cat
Russia Cat is a possibly large cat with long, dark, thick fur. The fur around his neck is white, a nod to Russia's scarf, though he lacked it in Volume 3. Like Russia, his nose appears to be rather prominent. When Finland was asked to obtain pictures of the Allied Forces cats, he described them as being free and uncontrolled thus "next to impossible" to get pictures of, however Russia Cat was drawn approaching the camera in a friendly manner, in front of what appeared to be a toy of some sort. In Volume 3, it's shown that he is the pet of Russia and was happy that the other cats were lively as usual. Because Russia and Italy's bosses had been getting along, he wanted to get along with the Italy Cats as well. However, when he went to their home, he saw them fighting, and placed himself between them to put a stop to it. He became happy when he saw that they had stopped fighting, and said that it was the best when everyone's relations were good. In a Kitayume header image, he was drawn with a Russian flag ribbon around his neck. Belarus was drawn rubbing his belly at a great speed.

His cry was written as "nyafufufu"/"nyahuhuhu", meowing and laughing.

South Korea Cat
South Korea Cat is a white cat with black or dark grey spots on his head, left flank, right paw, and toward the end of his tail. He shares South Korea's curl, and appears to have similar eyebrows to England Cat. Like France Cat, he was drawn with a few sparkles around him. As he was depicted lying on a pillow, he may be South Korea's pet.

Spain Cat
Spain Cat is a white cat with pale brown markings on his back, flank, most of his tail, stopping shortly before the tip, and on his head, curving down between his eyes and over his ears. He wears a collar with a rosary on it.

Sweden Cat
Sweden Cat is a dark-colored (blueish in his color illustration) cat with longer, white fur over his chest. He wears a Swedish flag ribbon around his neck, though his is longer than the others' and is torn or ribbed at the ends. He has marks under his eyes to represent the glasses Sweden wears.

Taiwan Cat
Taiwan Cat is a white cat whose tail is dark at the tip. Under her head are two pink flowers. Because she was depicted as resting on a pillow in the Nation Cat summary, it's possible that she is Taiwan's pet. Compared to the other cats, she's rather small witch might mean that she is a kitten.

Turkey Cat
Turkey Cat is a brown cat with a Nazar-shaped mark on his left flank, a fluffy tail, a red bandana, and, most notably, a bag over his head with large, round eye holes cut out of it and a smile drawn onto it, likely representing Turkey's mask.

Ukraine Cat
Ukraine Cat is a cat with thick, fluffy, pale fur, and a stripe on her head, likely to represent what would be regular Ukraine's headband. Next to her was drawn "dodonyaan", a meow in reference to the similar-sounding bouncing sound Ukraine's breasts make.

Trivia

 * The cats all speak a single language. In a New Year's comic, America Cat wondered if Toshigami, the Japanese god of the year that Japan Cat told him about, understood the cat language as Japan Cat intended to pray to him for a good new year. Despite all speaking one language, it's possible they can also speak human languages, as Japan Cat seems to have spoken Japanese when Japan gave him tuna, much to his surprise.
 * The only cats who have canonically received names so far are Japan Cat (Tama) and North Italy Cat (Gino).