Warlord's Deathwheel

The Warlord's Deathwheel is a Horde-only motorbike mount. It was the winning entry in the Azeroth Choppers competition held in June 2014.

Source
The Warlord's Deathwheel was awarded for free to Horde players that logged into the game from August 1 to September 30, 2014. The achievement that rewards this item is Warlord's Deathwheel (achievement).

Mount Journal
''Often referred to as the "Goblin Lawn Mower", this growling behemoth treats enemies like they are made of grass... ready to be mown down.''

Trivia
The Mount Journal entry refers to Azeroth Choppers Episode 7, where Samwise Didier comments that when the Horde bike's engine would not turn over on the first try that "I'm expecting th-th-the roar of kodo beasts... it sorta sounded like a... goblin lawn mower."

During beta testing, the mount was in fact known as the Goblin Lawn Mower and the mount journal text was a little different: "Built by the rowdy engineers of the Horde, this growling behemoth treats enemies like they are made of grass... and you're here to mow it."

For a time it was also known as Hellscream's Hog with the following journal text "Built by the rowdy engineers of the Horde, this badass bike is bathed in the blood of bludgeoned enemies, making it just the right shade of red."