Earthwalker. For each card played into combat by the opponent, roll 2d4 and add that number to the level of this ally.
Copyrights:
TSR
Wizards of the Coast
This is an interesting ally that can be good if you plan to play few cards, but still win by level.
The Aurumvorax is a nice +6 ally that can earthwalk, making it a decent card to attack hidden realms with. Better yet, the more the opponent fights against it, the stronger it becomes.
For each card (note, not ally, or spell, but physical card) played after it into combat, the Aurumvorax's player rolls 2d4 and adds the level the the Aurumvorax. This can range from 2-8, and averages at +5. This means after the opponent playes 1 card, it will be a +8 to +14 (average of +11), 2 cards will cause it to be +10 to +22 (average of +16), and 3 cards means it will be a +12 to +30 (averaging at +21). This is a pretty heafty bonus for a single card from your hand. Therefore, it is a good card to protect with champions that protect their allies (like Tagor Mijor (15/IQ)).
This will show up in many fun decks, but very rarely in tournament decks, since most tourney decks win combat very quickly using instant victory cards (not levels).