Staff of the Light

Just to make things clear, but the listed quests here is only for Blood Elves. The other races get their own versions of these quests as follows:

Blood Elf: Journey to Orgrimmar This is offered in Silvermoon, Thunderbluff and Undercity and leads to Staff of the Light
Undead: Dark Cleric Cecil This is offered in Silvermoon, Thunderbluff and Undercity and leads to The Dark Cleric's Bidding.
Tauren: The Seer's Call This is only offered in Thunderbluff and Undercity and leads to A Seer's Staff

Two of the hobo races (Troll and Goblin) apparently do have breadcrumbs if you are leveling in Thunderbluff or Undercity zones, but they are not necessary if you stayed in Orgrimmar.

Goblin: Seek Brother Silverhallow leading into A Seer's Staff
Troll: Seek the Shadow-walker leading into The Shadow Walker's Task

Obviously, Orcs don't need breadcrumbs as Orgrimmar is their capital. They can just pick up the quest

Oddly Panda don't seem to get either a breadcrumb or the weapon quest either for priest class. They do get the basic orc weapon quest for hunter, and probably other classes so I don't see why they don't have the priest version.

EDIT - Support got back to me regarding Panda, and it looks like you guys are giant, furry Goblins. There's still no available breadcrumb, but it seems you share the Goblin version of the priest weapon quest.