Grr, for some reason this did not unlock for me just now. I was doing the final map of the 3 for the Fated Traveler Achievement with my Goblin Deck. 2 Things I did tho that I hope didnt cause a problem.
1) I played the game in 2 sessions so I had to resume the suspended Game. I did get the Fated Traveler Achievement, but no Chief of Goblins Achievement.
2) I raised my Red Cap to 380/380. but I had 3 on the board, one of the others, I had to 320/320 at one point. The Last I never used in battle. Think there can only be 1 Red Cap on the Board at a time, and if there are multiples, do they all have to be raised to over 300/300?