Wallmonger

Wallmonger is a boss found in the Hollow.

Behavior
Wallmonger spans the entire width of the room, with its "face" in the center. It continually moves downwards, and if it is not killed by the time it reaches the end of the room, the player will be instantly killed. Wallmonger has a variety of attacks:
 * Spits a trail of fire down the center of the room, followed by firing large blocks of bullets down each side while also firing spreads of bullets.
 * Fires alternating spreads of bullets that widen as they travel down the room.
 * Fires expanding rectangular formations of bullets.
 * Fires a line of waving bullets that spans the width of the room.

Tips

 * The large blocks of bullets that are fired when there is fire in the middle of the room can be avoided by dodging right through them.
 * However, this does not work when the player has items that slow down enemy bullets, such as Liquid Valkyrie or Bloody Eye.
 * Items that grant the player flight and items that grant fire immunity make the fight a bit easier, as the fire trail actually becomes a safe space.
 * Mega Douser can extinguish the flames in the center, making the fight slightly easier.
 * Bug Boots can replace the flames with poison to similar effect.
 * Beware of dropping items during the boss fight, as they can become inaccessible afterwards due to Wallmonger moving and dying on top of the items. This is especially important when carrying the Busted Television.

Trivia

 * The Wallmonger may have several influences:
 * One such source of inspiration is the Wall of Flesh from Terraria, who needed to be killed before it forced you to the edge of the world. Backing this up is the fact that there seems to be corpses inside the wall.
 * Another possible inspiration is the Demon Wall bosses from Final Fantasy.
 * Or the Living Wall from Advanced Dungeons & Dragons 2nd edition.
 * Or Wall Face/Doom's Wall in Secret Of Mana.
 * Or The Nuclear Throne enemy, from the game of the same name.
 * Or the Source Wall of DC Comics, given the embedded Gundead within it.
 * Or the wall of dead soldiers built in the movie 300
 * The Wallmonger's fight can only be accessed if the boss room door is on the left or the right, because Wallmonger only moves forward.
 * The name Wallmonger is a portmanteau of wall and warmonger.