I think it is not a rule to have the same quanta for each ability. Growth is a good example.
Who said devouring darkness doesn't exist. (You were eaten by a grue).
There are a lot of ways to buff this critter to be able to eat something, or just kick of with sparks.
So, it is fine. The unupped version is probably never used. But i don't see that as a problem.
Btw, this weakens the fate egg a little
Kael: if all new creatures are just stronger and stronger, it would make the Fate Egg and other similar effects stronger and stronger too.
It doesn't hurt if people add weaker than average creatures as long as they are stronger than the weakest one and have some utility.