Demolitionist Legoso is a level 20 quest giver located at Vindicator's Rest in the draenei territory of Bloodmyst Isle.
He starts the quest [20G] Ending Their World.
See List of Bloodmyst Isle NPCs.
This section concerns content exclusive to Wrath of the Lich King.
Legoso eventually becomes a senior demolitionist and can be found in Wintergrasp.