Hobbit Bonus Card Specualtion Mentions
For everyone saying that the Unseen Bonus Card will be Mithril Coat, that doesn't make sense because that is not what makes Bilbo invisible. it either has to be a One Ring or a Treasure Token.
Again at the and of the description it says: "Just mind your step. There are older things than goblins in the deep places of the world, and some treasures are better at finding keepers than being found."
Or we get shafted and I paid 120+ for 13 dollars worth of cards. They're beautiful at least.
Edit: nor Whisper Silk Cloak, it doesn't line up flavor wise or with the riddle. The whole point of being "Unseen" is the One Ring. This Isn't Harry Potter smh