Minecraft wiki entry for Defeating_an_End_city, associated text: The totem of undying can also be used, but it can only be accessed after you explore a woodland mansion or defeat a raid. However, it is absolutely worth it, because will prevent you from dying. To use it, simply place it in your off-hand and ignore that it is even there while you explore. When you take fatal damage, the totem will explode and cause an animation of fireworks, which will "resurrect" you and provide you with Regeneration and temporary Absorption.