The place from where nexon takes ideas for new pets

Also, concept art -> production -> implementing in game. It probably hit a snag with something like copyright. :/

I doubt it. I'm sure there was all kinds of legalese involving the transfer of rights.

im about 99% sure that if nexon copyrights the image before the artist does, they get the copyrights.

You don't need to apply for a copyright. The copyright simply exists as soon as the work is created.