The Elder Scrolls IV: Oblivion/Cheydinhal Quests

The Renegade Shadowscale
Speak with Teinaava after completing The Lonely Wanderer of The Dark Brotherhood quests, to flag this side quest. This is a pretty simple assassination. Go to Bogwater, close to Topal Bay, South-East of Leyawiin. Sneak up on Scar-Tail and get your critical attack on him and then finish him off. Loot his body and remove the heart. Travel back to Teinaava in the Cheydinhal Sanctuary to receive the Boots of Bloody Bounding.