Added in Ultimate Expert Mode. Now when you kill mobs in this mode, they only drop themselves. This also applies to bosses. Also you only have 1 health and all characters are set to Hardcore mode upon loading an Ultimate Expert Mode.
All boss and enemy life/damage/defense increased by Graham's Number to the power of a Googolplexian times TREE(3).
Bosses don't drop anything besides a special Lifeless Mode-exclusive item, which always negatively impact the player.
King Slime - Unroyal Gel - King Slimes spawn instead of normal slimes when equipped.
Eye of Cthulhu - Shield of Sadness - Attempting to dash will kill you.
Eater of Worlds - Deadly Scarf - 1700% increased damage dealt to the player
Brain of Cthulhu - Brain of Nausea - Player has constant confusion and 15 damage per second
Queen Bee - Hive Trophy - Bees fired from Bee Gun, Bee's Knees, Bee Keeper and Beenades will attack the plaer
Skeletron - Bone Gauntlet - Will eliminate half of the Town NPC population and will instakill the player.
Wall of Flesh - Deadly Heart - Deletes all accessory slots.
Mechanical Bosses - Mechanical Nuke, destroys the entire world and spawns every mech boss
Plantera - Poison Sac, constant venom and poison inflicted to the player.
Golem - Nothing.
Lunatic Cultist - Nothing.
Moon Lord - Does not exist in Lifeless Mode, instead instantly crashing the game.