Wand of Holiday Cheer

The Wand of Holiday Cheer casts an area of effect spell which causes everyone within range to laugh. Because the wand does not carry a specific number of charges, there is no limit to the number of times it can be used. Ten days after obtaining the wand, it automatically disappears from your inventory.

Source
This wand is only available during the Feast of Winter Veil. It is obtained by opening a, found under the holiday tree near the bank in Ironforge.