The Lich is a powerful undead creature located in the fourth floor of the Slayerdungeon of Prifddinas (along with two other liches). As is it classed as undead, the Lich is weak to both light spells and a Darklight/Silverlight, along with these the lich is also weak to bolts. The three weaknesses make it very flexible for players hunting down Liches as they can use any of the three attack styles(provided they use the correct weapon/spell). Killing at least one Lich each time a player enters the fourth floor of the dungeon is required in order to attack Rho'mox the Toxic.
The Lich has a special attack with which it binds the player for 4 seconds, and every attack form the creature hits through armor while the player in stunned. While stunned the player is unable to eat and any activated prayers are deactivated. The special can easily kill a player who let their health drop too low before the attack. After using the special, the Lich is unable to cast the special again for 4 auto attacks. The special can be avoided if the player efficiently uses the Anticipatation and Freedom abilities in order to avoid being stunned.