When anonymous posts were allowed, some spambots filled the page where this picture was originally posted. The posts from spambots were enormous and any bump to it meant that most the Comments section was occupied by only one image.
Starting with the hat and in clockwise order... A lot of random scientific terms so I hope I got them right.
[Hat] Without this, the Yukkuri can't take it easy. On top of that, its used as recognition and a yukkuri without a hat/accessory is despised above all other things, and will be killed.
[Skin] Main component is flour. Breaks easily.
[Central Paste Core] If this is missing or if 2/3 of the total filling is missing, the yukkuri will die.
[Bean Paste] Differs between the various species, but there's quite a bit usually.
[Hair] Mostly comprised of sugar. A thinly threaded hair-like substance.
[Foot] Moves according to the movement of the paste inside the body.
[Anal] Expels old bean paste from the body through this orifice. Even if its "old", the paste is not rotten yet.
[Pee-pee hole] Expels the excess moisture from the body in the form of sugar-water.
[Peni-peni (Mamu-mamu)] Reproductive organ stemming from the body. The pole-shaped one is peni-peni, and the orifice shaped version is mamu-mamu. It receives the seminal-paste fluid, and the baby will be born here after being conceived.
[Mouth] Takes in the food to be absorbed into the body.
[Teeth] Grown from the paste. When born, the teeth are already permanent teeth but even then its fragile and breaks easily.
[Eye] Eye-shaped gelatin. With this the yukkuri can see.