Board Thread:Spoilers!/@comment-5899967-20150208192922/@comment-2153169-20150417064557

SnowKingTE wrote: The explanation of why Cruella and Ursula didn't age was kind of confusing. do dragon eggs give you eternal youth or something?

I think they just reused the magic from the egg. Look Regina in s1, she used the magic from her ring to gain the ability to use magic in the LWM. I think it is prolly something similar in this case :)