Tumeken's shadow is a monster fought during the Missing My Mummy quest found inside the pyramid south of the Ruins of Uzer. Players must defeat him to "re-unite" his shadow with his body.
Players gain Magic experience every time they kill one of its five forms. Each form gets stronger than the last one defeated. Each shadow earns the player 4% completion, so defeating all 5 forms earns a total of 20% completion.
Tumeken's shadow is created by lighting braziers in Uzer Mastaba, the main location of the quest. The braziers will cast light on one of the four statues of Tumeken around the room. The shadow cast by the statue then rises up and becomes Tumeken's shadow.