From WoWWiki

Fresh Holly can be used while riding a mount and will transform your mount into a reindeer until you dismount. Flying mounts can still fly, and will lift off with a jingly bell sound, leaving an energy / snowflake trail. Fresh holly has a 7 day duration

Source

Obtained during the Feast of Winter Veil seasonal event by kissing the special holiday NPC found in Inns standing under some mistletoe.

Note

• There is also Preserved Holly, which does the same thing, but will never expire.

External links

Neutral Mounts
Class Based	Death Knight: Deathcharger Paladin: Warhorse • Charger Warlock: Felsteed • Dreadsteed
Pre-Burning Crusade Drop Mounts	[Deathcharger's Reins] • [Swift Zulian Tiger] • [Swift Razzashi Raptor] •
Burning Crusade Drop Mounts	[Ashes of Al'ar] • [Fiery Warhorse's Reins] • [Reins of the Raven Lord] • [Amani War Bear] • [Swift White Hawkstrider] •
Faction Mounts	Riding Talbuk • War Talbuk • [Cenarion War Hippogryph] • Nether ray • Netherwing drake mounts
Crafted Mounts	[Flying Machine Control] • [Turbo-Charged Flying Machine Control]
Holiday Mounts	[Fresh Holly] • [Preserved Holly] • [Brewfest Ram] • [Swift Brewfest Ram] • [Magic Broom] • [Swift Magic Broom] • [Flying Broom] • [Swift Flying Broom] • [Rickety Magic Broom]
TCG Mounts	[Riding Turtle] • [Reins of the Spectral Tiger] • [Reins of the Swift Spectral Tiger] • [X-51 Nether-Rocket] • [X-51 Nether-Rocket X-TREME]
Other Mounts	Qiraji battle tank mounts • [Black Qiraji Battle Tank] • [Dark War Talbuk] • [Dark Riding Talbuk]