Stalker is one of the assassins that appears in the game. After the player slays the boss, he/she will receive a message from him. After this happens, there will be a small chance, that he will apear during the mission, lock down the current map section, and beggin his hunt. Using his Dread bow, Despair kunai, and Hate scythe, he may be a huge problem, especially for the new players, or those with low lvl. equipement. After "The Second Dream" quest, a shadow Stalker will appear instead. Weilding his War greatsword, and some Sentient abilities, including ability to adapt to the damage.
stalker (warframe)