The squiggly line representing the high frequency “spirit” of Yomni
Yomni being both outside of spacetime and within it, but split into constituent parts: Yarghazar, Yachtipuss, and spirit/consciousness. In this representation, Yomni is outside of time, but creates time and space (Yoniverse) and puts itself inside of it into four parts: the Yachtipuss, the Yarghazar, the consciousness of Yomni, and as a byproduct, the Yonians.
Yello has special properties which make Yonians unique and powerful (regeneration, absorbtion & conversion of matter) - so I suggest Yonians should be the only beings from Yello. The origins of other life in the Yoniverse could mimic something similar to our own universe. Maybe there were instances in time (and ongoing instances) where an area in the Yoniverse becomes so heavily and densely concentrated by Ysmig that Yectoplasm forms materially and this is what evolves into the different creatures and beings in the Yoniverse. This Yectoplasm and the beings formed thereof are reflective of Yomni's state & disposition when the Yectoplasm forms.