In Wrath of the Lich King it is item level 226, requires level 80 and is named Dreamwalker Trousers. In MoP Classic it is item level 213 and requires level 80.
Read from the World of Warcraft client build files (JournalEncounterItem, JournalEncounterCreature, Achievement) and the Blizzard Game Data quest API.
How Valorous Dreamwalker Trousers Compares
Who It Suits
Leather is the armor type Demon Hunter, Druid, Monk and Rogue wear. With Agility or Intellect, Valorous Dreamwalker Trousers suits Assassination, Outlaw and Subtlety Rogue; Brewmaster, Mistweaver and Windwalker Monk; Balance, Feral, Guardian and Restoration Druid; Havoc, Vengeance and Devourer Demon Hunter.
Transmog Sets
Valorous Dreamwalker Trousers is part of the transmog set Valorous Dreamwalker Battlegear (Druid only). The other 16 pieces:
Items Numbered Next to Valorous Dreamwalker Trousers
Blizzard numbers items as they are created, so the named items next to ID 40468 (40462 to 40473) were usually added in the same batch as Valorous Dreamwalker Trousers: the same quest line, zone, vendor or reward set.