Obtain Invincible from Arthas in Icecrown Citadel.

Obtain The Horseman's Reins from The Headless Horseman in the Scarlet Monastery during Hallow's End.

Obtain a Grand Black War Mammoth.

Defeat Yogg-Saron in Ulduar on 10 or 25-Player Pre-Nerf difficulty, before the release of the next raid tier.