Board Thread:Dragon City Gameplay Questions & Answers/@comment-10724830-20130627192741/@comment-10090661-20130713060425

Robot Dragon is actually only a Collector's Dragon -- at least, that's the way I see it. Not much use for anything  except to stick it in your PVP team so that people battling you will have an unusual dragon to fight. =D

(My PVP team consists of one Dark Hybrid lv4 + Cerberus lv4 + Demon lv4, like a mini Dungeon Quest. xD Except of course I don't give you my dragons after you defeat them, and they're no biggie to defeat. lol I blame my choices for PVP team on Jens. He stuck me with the idea that you should leave a weak nominal team for other PVP players.)

So, no -- DON'T sell off your Robot Dragon. It is unlikely you will ever be able to replace it, and anyway it's not much use for fighting. If you don't want to call it a Collector's Dragon, maybe you can call it a Decorative Dragon. =D