Riding Crop

Riding Crop is a craftable trinket which increases a mount's speed.

Source
Riding Crop is crafted by Leatherworkers with a skill level of 350.

The pattern is sold by Thomas Yance in the Old Hillsbrad Foothills for.

Trivia

 * During the Burning Crusade beta tests, the trinket had an on-use effect to increase mounted speed by 25% for 10 seconds.
 * The Riding Crop was temporarily available as an artifact in Heroes of the Storm.
 * A riding crop enchantment briefly existed during the World of Warcraft: Wrath of the Lich King beta but was eventually scrapped.