Invincible's Reins

Invincible is a flying mount obtained when defeating the Lich King "in his strongest form" on heroic difficulty in 25-player mode only. Prior to patch 4.0.3a this mount was a guaranteed drop. It was changed to a very low chance drop.

It can also be listed on the Black Market Auction House by Mei Francis, for the opening bid of.

Mount journal
''The famous steed of Arthas Menethil, who serves its master in life and in death. Riding him is truly a feat of strength.''

Achievements
Obtaining this mount awards the Feat of Strength Invincible's Reins (achievement).