Crypt Lurker is an enemy in The Catacombs. They very rarely drop Premium Flesh.
Like any other Dungeon Mobs, it can have modifiers such as Healthy, Flaming, Stormy, Speedy or Fortified. Healthy increases the mob's ❤ Health. Fortified increases the mob's ❈ Defense. Flaming makes melee attacks light the player on fire. Speedy makes the mob move much faster. Stormy makes the mob strike lightning on nearby players, dealing ✷ True Damage.
Crypt Lurkers have a bone when they are spawned, and can throw that bone dealing massive damage. However, after they throw the bone, they act like normal zombies and are no longer threatening and can easily be defeated. The bone can also be easily dodged.