In the new TCG expansion "The Dark Portal" is available. This item will be released as the uncommon loot from the WoW TCG Expansion "Betrayal of the Guardian". I have this hearth and it is amazing how many ??s and !! I get when they see this thing casted. The best part about it. The Dark Portal lingers behind from the place you hearthed from. You can watch then as 5-10 people run back and forth thru it to try to use it as a real portal!

The loot items from this set are:
Gusting Grimoir (1/3)
Dark Portal (2/3)
Ghastly Charger's Skull (3/3)

Do a little bit of research, I apologize I could not post a picture but I am sure someone else will take the opportunity too. Wowhead has many screenshots available.