If you have ever heard the above word before, you have no doubt borne witness to it in some form of Japanese monster culture. Yu-Gi-Oh! has a few Momonga cards and Pokemon just got another electric squirrel in Generation V:
Japan has several species of flying squirrel. They can all be referred to as "momonga," but the 'true' momonga is the Japanese dwarf flying squirrel (Pteromys momonga). I'll let that sink in before I post the pic. Dwarf. Squirrel. That flies.
How did nature make something so goshdarn cute? You might be able to blame insular dwarfism; sometimes, when creatures evolve on islands, they get substantially smaller than their mainland counterparts. Japan also has another giant momonga, which may be the opposite case (insular gigantism). In the end, it really does not matter: They are adorable.
Momongas, as well as other flying squirrels, do not actually fly. They have a flap of skin called a patagium in between their forelimbs and hindlimbs. "Parachuting squirrel" does not have the right ring to it, even though it would be more accurate.
The ugliest momonga picture science could manage.
The momonga is native only to the sub-alpine forests of Japan. It eats seeds and fruits - you know, like most squirrels do. As the big eyes might have hinted, the momonga is nocturnal. It is threatened by habitat loss, but not enough to make it a super-endangered animal (instead listed as least concern).
By the way, be careful looking this little guy up on YouTube; I have seen a few sugar gliders posing as momonga. Those are cute, but not the dwarf flying squirrel. (They are actually marsupials, for starters; the Japanese use the term "momonga" to describe them regardless.) For future reference, here is a picture of the culprit:
Truly the eyes of a con artist.
Japan is capable of great atrocities and great cuteness; that is why they can make both tentacle porn and Hello Kitty. (For your own sanity, do not combine those two images in your head. Have a cute video to push that nasty image out.)
If this squirrel does not kill you by sheer cute, then you do not have a soul.