Once you reached a certain level you will be able to pass down a feature from one of your panerugas to a myo paneruga, that hatches from one of your eggs:
To pass down a feature to a MYO you own that didn´t hatch yet, go here.
How passing down works (last update August 2020)
Make sure to register each new level
LV 10: Your Panerugan can pass down one of the features it has to a MYO (Egg) of a species you own.
LV 20: Your Panerugan can pass down two of the features it has
LV 30: Your Panerugan can pass down three of the features it has