<p>The ones that I know of are:</p><table border="1" cellpadding="1" style="width:500px"><tbody><tr><td><strong>Boss</strong></td><td><strong>Quest</strong></td></tr><tr><td>Pythius the Rotten</td><td><a rel="nofollow" href="https://tibia.fandom.com/wiki/The_Hidden_City_of_Beregar_Quest">The Hidden City of Beregar</a></td></tr><tr><td>Armenius</td><td><a rel="nofollow" href="https://tibia.fandom.com/wiki/Blood_Brothers_Quest">Blood Brothers</a></td></tr><tr><td>Zalamon</td><td><a rel="nofollow" href="https://tibia.fandom.com/wiki/Wrath_of_the_Emperor_Quest">Wrath of the Emperor</a></td></tr><tr><td>The First Dragon</td><td><a rel="nofollow" href="https://tibia.fandom.com/wiki/First_Dragon_Quest">First Dragon Quest</a></td></tr><tr><td>Azerus</td><td><a rel="nofollow" href="https://tibia.fandom.com/wiki/In_Service_of_Yalahar_Quest">In Service of Yalahar</a></td></tr><tr><td>Planestrider</td><td><a rel="nofollow" href="https://tibia.fandom.com/wiki/Opticording_Sphere_Quest">Opticording Sphere</a></td></tr><tr><td>Thaian</td><td><a rel="nofollow" href="https://tibia.fandom.com/wiki/Feaster_of_Souls_Quest">Feater of Souls</a></td></tr><tr><td>The Source of Corruption</td><td><a rel="nofollow" href="https://tibia.fandom.com/wiki/Cults_of_Tibia_Quest">Cults of Tibia</a></td></tr></tbody></table><p>Other Souls</a></td></tr></tbody></table><p>Other NPCs that can be killed </p><ul><li><a rel="nofollow" href="https://tibia.fandom.com/wiki/Armenius_(Creature)">Armenius</a> (There is only a chance you will face during the Blood Brothers quest)</li><li><a rel="nofollow" href="https://tibia.fandom.com/wiki/Owin_(Creature)">Owin</a> (Chance to be found when there is a full moon on Grimvale)</li></ul><p></p>