These items are rare, hard to win, give special powers during battles and rate the highest resell values for shards and jewelry in Free Realms. You can win them for all the jobs that require battling. I do not yet have one character that has managed to win them all...and I have been playing Free Realms almost since its inception. Good luck!

The Ghost of Bergram Stumpfinger in Blackspore: Necklace of Power Font.
Mudshell in Blackspore: Power Shard of Entangling.
Fallen Snowmen in Snowhill: Necklace of Agility.
Robgoblin Boomers near the Durango Zoo and tin mines: Ring of Shielding.
Wraiths of Wrath in Blackspore: Power Shard of the Vampire.
Hooligan Delinquents in the South Wildsower Shard of ?
Mushroom Pests in Briarheart: Power Shard of the Armadillo.

(Since Free Realms is offline, I am trying to do this from memory. I fear my memory has failed me for some of the items and I might have mixed up some of the games with the prizes, but this is the best I can do for now. I'll try to update this when Free Realms comes back online. Also, others may wish to add their knowlege of these or similar items. Thanks).