The Wrath of the Lich King Classic PTR has been updated to Patch 3.4.3 Build 51831, which included two new mount models, the Magic Rooster and the Blazing Hippogryph. There is currently a promotion on Taiwan Realms for Wrath Classic players, after purchasing 90 days of game time you will be rewarded with the Magic Rooster.
Both the Magic Rooster and the Blazing Hippogryph were previously available as TCG Loot Cards, releasing in 2009 and 2010.