The Grateful Dead

This is the [race=4] version of the quest, only available on the Day of the Dead. Go to the graveyard in Darnassus (see map). Buy an [item=46718] from [npc=34382], or a [item=46861], or get your old one out of the bank. Use it, gain [spell=65393], and suddenly you will be able to see lots of [npc=35250]s, [npc=46894]s, one [npc=46908] (not for you!), and one [npc=34479] who offers this quest. He wants [item=46691]. Hungry! Buy a [item=46710] from Chapman if you don't know it already. Head over to [npc=4223] to buy Simple Flour. Ice Cold Milk is easier to come by, but [npc=4167] is the nearest vendor who sells it. Head back to the graveyard, and behind [npc=34383] is a small brazier, with a blue flame. It's not labeled, but that's the Ghostly Cooking Fire, and it's required to bake your dead bread. Use a Marigold again, turn in the quest, and receive your [item=46831]. While you're there, /dance with Catrina for [spell=65386] (a nice costume change), and Dead Man's Party if you don't have it already.

Other items you have collected over the years that allow you to see dead people (e.g. [item=22115]) don't work here, nor does being dead yourself. This year, even if you've done this quest in previous years, you can do it again. Thanks to others above who already shared some of this info.

Some insight about the Grateful Dead:

Grateful Dead in Folklore:

Grateful dead (or grateful ghost) is a folktale present in many cultures throughout the world. The most common story involves a traveler who encounters a corpse of someone who never received a proper burial, typically stemming from an unpaid debt. The traveler then either pays off the dead person's debt or pays for burial. The traveler is later rewarded or has their life saved by a person or animal who is actually the soul of the dead person; the grateful dead is a form of the donor.

Grateful Dead in Music:

Grateful Dead was an American rock band formed in 1965 in Palo Alto, California.The band was known for its unique and eclectic style, which fused elements of rock, folk, bluegrass, blues, reggae, country, improvisational jazz, psychedelia, and space rock, and for live performances of long musical improvisation.

It seems you have to get the quest in graveyard for your race's capitol city.