The Ninja Master is an NPC involved with the Death Lotus Training event. Talking to him for the first time of every prestige will complete a kebbit-level task, and yield either a skill-specific small XP lamp or a small prismatic lamp (dependent on his location) and two shuriken stamps.
The Ninja Master teleports around occasionally, therefore the location he may be found in varies. His location differs per world. The Death lotus training scroll must be brought to complete the kebbit-level task. He will only give the lamp and stamps if you selected "I'm ready to learn!", but the task will still count as done if "I know everything already." was selected instead. Players who want to complete the task but retrieve the lamp later may do this.
|Ardougne, east of the gem stall and between the houses||Thieving|
|Fremennik Slayer Dungeon, in the passage between the kurask and the aquanites||Small prismatic lamp|
|Gnome Stronghold Agility Course, on the platform past the rope balance||Agility|
|Ice Mountain, on the nortwestern peak near the Oracle||Hunter|
|Kharidian Desert Bandit Camp, in the northeastern corner of the bar||Thieving|
|Lumbridge Swamp, right outside the shed that takes you to Zanaris in Lumbridge Swamp||Thieving|
|Slayer Tower in Canifis, in the northern part of the groundUK], just south of the throne floor[||Slayer|
|Taverley Dungeon, in the northern part of the poison spider area||Herblore|
|Thurgo's Peninsula, just south of Thurgo's hut||Smithing|
|Varrock Museum, 1stUK] floor[||Small prismatic lamp|
A good way to meet him is to go to one of these locations and hop worlds until you see him.