<p>I would say the hardest monster to complete bestiary are:</p><ol><li><strong><img src="https://static.wikia.nocookie.net/tibia/images/1/15/Midnight_Panther.gif/revision/latest/scale-to-width-down/64?cb=20140123150714&path-prefix=en" alt="Midnight Panther.gif"> Midnight Panther.gif" src="https://vignette.wikia.nocookie.net/tibia/images/1/15/Midnight_Panther.gif/revision/latest/scale-to-width-down/64?cb=20140123150714&path-prefix=en" style="height:64px; width:64px"> Midnight Panther:</strong> not so much for the amount needed (only 5), but for the difficulty of finding the creature</li><li><strong><img src="https://static.wikia.nocookie.net/tibia/images/2/21/Sight_of_Surrender.gif/revision/latest/scale-to-width-down/64?cb=20131126124909&path-prefix=en" alt="Sight of Surrender.gif"> Sight Surrender.gif" src="https://vignette.wikia.nocookie.net/tibia/images/2/21/Sight_of_Surrender.gif/revision/latest/scale-to-width-down/64?cb=20131126124909&path-prefix=en" style="height:64px; width:64px"> Sight of Surrender: </strong>these creatures are very difficult to kill due to their high number of hit points and armor / resistance.</li></ol>