I have been checking how some to possible "adopt"

Question:

If they have never been in a battle or a mission (based upon the profile)

Why would one be at level 0 and another be at level 59 or 60?

I have some of the Kismet Dragon Sylvorpa's so this question also applies to them.

Thank you.

If a themed pet is level zero,it means it has hatched from an egg (as with the Kismet Dragons).

Any themed pets on higher levels...
if they have never been in a battle or on a mission (like, say this one or this one), they were obtained from the wild in one of the seasonal festival zones.
In the seasonal festival zones, the level of the wild opponents scales roughly with the level of the highest pet in your party (the fae was caught with our team all level 60. However, the levels never go below ten and obviously not above level 60 (yet)).

Alternately, they were hatched from an egg and have been given exp orbs to raise their level.

Thank you so very much - that makes sense - I was actually looking at the price of the experience orbs and wondering if they are worth the investment for 60 / 0 combinations for breeding.

I have also found a few on abandoned accounts and wondered if level of care might have helped