Bio
The Wall of Flesh is the final and strongest pre-Hardmode boss, spawnable only in The Underworld. Once it is defeated, the world permanently converts to Hardmode, which brings new content and challenges. This means that once the Wall is defeated, new biomes will spawn, new monsters will attack you, and the game can be beaten.
To defeat the Wall of Flesh, the player must attack either its eyes or its mouth. They all share the same life counter, so attacking any of the two will deplete the total health of the boss. However, the eyes have less defense (thus take more damage) than the mouth. No other parts of the Wall can be damaged.
See below for information on the two exclusive debuffs from the boss, Horrified and The Tongue.

Spawn Conditions

The Wall of Flesh is summoned immediately 75 blocks away from all visible players when a Guide Voodoo Doll is destroyed by being dropped into lava in the Underworld while the Guide is alive, killing the Guide. Dropping the doll into lava outside of Underworld, regardless if the Guide is alive, will not spawn it, and the Voodoo Doll is destroyed with no effect. In the PC version, Console version, Mobile version, and tModLoader version, the Wall of Flesh can also be summoned by letting the Guide be killed in the Underworld while the Guide is in contact with lava. Using this method, the Guide can die by any means, either from a player, an enemy or the environment, as long as he is touching lava when he dies.If a Mediumcore player dies in lava (in the Underworld, and Guide is alive) with a Guide Voodoo Doll in their inventory, the Wall of Flesh is summoned.

Stratigies
• Mobility-enhancing items, such as Gravitation Potion, Rocket Boots or one of their upgrades, and various hooks can make traversing The Underworld much easier. Also, flying mounts such as the Honeyed Goggles are good to go over the pools of lava. Similarly, items like Obsidian Skin Potions, Lava Charm, Lava Waders, or an Obsidian Rose can mitigate The Underworld's many lava pools and other ambient hazards.
• Using both the Magiluminescence and the Lightning Boots increases the player's top speed to 41 mph, enough to always outrun the Wall of Flesh in classic mode.
• Heart Arrows will freeze the Wall of Flesh in place, as long as the arrows hit its mouth.
• Beenades and Molotov Cocktails are highly effective throwing weapons against the Wall of Flesh, especially in Expert Mode.
• Melee weapons are not recommended for fighting the Wall of Flesh for the first time, because the close range of this class results in a sizable amount of contact damage. Certain melee weapons with extended range, like the Dark Lance, Yoyosand Flails might prove useful.
• Equipment that inflicts On Fire! are effective against The Hungry.
• An effective and common terrain preparation consists of building a long bridge (at least 500 tiles long in Normal Mode and even more in Expert or Master). Wood Platforms or Hay blocks are suitable materials due to their abundance. Ruined Houses and hills of Ash Block on the bridge should be cleared to avoid getting stuck during the fight.
• Making the bridge out of Explosion-proof tiles (such as Dungeon Bricks) and using Dynamite can be extremely effective if a player times their throws well.