Ogre Pinata, chock full of chewy bubbly bubble gum! He's fat, pink, and breaks open once beaten to death. The prize is a lootable pile of bubble gum which, when used, will let your character run through dragonslaying raid and fiercely contested battlefields with a big wad of bubble gum blowing out of their face.
The best part is, you don't have to be in a party or raid to loot the gum. If you can see it, you can loot it.
I know a player who used to pull this out before every boss attempt in Icecrown Citadel. It became a thing. Soon after the introduction, the raid began to demand the pinata as a lucky charm before the real fights began. Imagine 25 battle-hardened raiders, staring intently at Arthas, waiting to engage, all blowing giant pink bubbles. It was quite a sight.
This one's pretty easy to get. You can buy the WoW-TCG Card from any of the fine vendors out there, or you can buy booster boxes and packs from the Fields of Honor set and hope to score one that way.