<p>To my knowledge, there are two theories about what causes the curse: Having stepped inside the Tresure Treasure room in Cobra Bastion (floor +3, same as Gaffir), or having used The Supreme Cube recently. The curse doesn't show on your character through any signs, although you can observe the effect of a floating Supreme Cube on yourself as you land on Cobra Bastion (might be unrelated if the cube is not what triggers the curse)</p><p>According to TibiaWiki, <em>to remove the curse you have to go to the +3 floor and toss some gold on the floor there (<a rel="nofollow" href="https://tibia.fandom.com/wiki/Strange_Rat">link</a>)</em></p>