I believe that the COP is a rookie, thus my vote for the trigon. My deck is mono-green and it rocked against me.I vote for Spiderman's CoP: Green. I'm pretty sure I'm the only player significantly affected by it, but that was definitely the game-changer this game (as much as I'd like to vote for an objectively more powerful card, this is the one that destroyed me in the last game).
I did not see the COP in the second game, thus no vote for it.Edit: Apparently last time you wanted to vote for the Deathbringer Liege (not the CoP), which is a rookie.