Nightmarish Hitching Post
Source: Promotion. The Nightmarish Hitching Post is send to players who have purchased the from the Blizzard Store ($30).
The 
Nightmarish Hitching Post is a toy mailed automatically to players who purchase the 
Warforged Nightmare from the Blizzard Store for $30, allowing party members to temporarily ride a Warforged Nightmare for 20 minutes.
Guide awaiting review
Purchase the Warforged Nightmare
Buy the Warforged Nightmare from the Blizzard Store for $30. The Nightmarish Hitching Post will be sent to your mailbox automatically, including the mailboxes of all your low-level alts, with a note from the Forgotten Smith explaining it was crafted from leftover materials.
Use the Hitching Post
Place the Nightmarish Hitching Post on the ground and have party members click it to transform their mounts into a Warforged Nightmare for 20 minutes. Party members must have at least Apprentice Riding skill to mount up — characters at levels 1–19 cannot use the post.
Understand the buff behavior
The buff replaces your current mount entirely for its duration, meaning mounts with special abilities such as passenger carrying or water-walking will not retain those abilities while the buff is active. The buff also persists through death.
Tips
Using the
Oddly-Shaped Horn while under the Nightmarish Hitching Post buff provides an instant mount without consuming a charge.
