(see Premature Yukkuri for premature pregnancies) A Koyukkuri has always the same characteristics as one of its two birth parents, only smaller. Their smaller size and utter lack of skills make them extremely frail, to the point that some authors have named them Walking Death Flags. Their survival rate is dim at most since birth, thus the extremely high birth rate of the average yukkuri is the only thing keeping the race as whole going.