Frost Moon

The  is an event triggered through the use of a Naughty Present, which is made using materials only available in Hardmode. It is the Christmas counterpart of the original Pumpkin Moon with increased difficulty, making it the most challenging event introduced thus far. It has 15 standard waves as well as 5 extra bonus waves.

During this event, the moon changes color to look like the face of a snowman.

Aside from the unique rewards you can get from the monsters in Frost Moon, this is also a very good source of Presents.

The Event
Like the Pumpkin Moon, there are a number of waves in the Frost Moon, and waves progress as you kill Frost Moon Enemies. Each Frost Moon enemy awards a differing number of "points" when killed. After a wave's points threshold is met the next wave begins, and the points score is reset to 0. When the player reaches Wave 15 there is a 25% chance each Ice Queen, Santa-NK1 and Everscream killed will drop their respective trophies. This increases to 33% at Wave 17 and 50% at Wave 19.

If the event is not completed by sunrise (4:30AM) the event will simply end.

The preparations
Due to the fact that this event is EXTREMELY hard, it is highly recommended (if not outright mandatory) to wear top-notch end-game equipment. It is furthermore highly advised to build an arena with traps (Lihzahrd-type ones) and lava to help deal with the waves of monsters, much in the same manner as with the Pumpkin Moon. The arena should also feature a nearby house serving as a spawn-point for dead players. Wounded monsters will regain full life if the house is too far away. The event lasts throughout the night only and will end on 4:30am, making high damage a must to properly advance and obtain loot.

Mage set: The mage set is perhaps the most powerful set due to the armor's ability to heal the caster and his/her allies. Despite making the wearer somewhat fragile, the healing output has the potential to usually pull through. With the game featuring some powerful magical weapons, the mage set can provide the greatest healing currently possible (surpassing the Vampire Knives). This makes it very nifty for multi-player and extremely recommended for single-player. The currently best magic weapons are the Blizzard Staff and Razorpine, though with these coming from the Frost Moon itself the player may try obtain any of the other weapons first. It should be noted that although the Nimbus Rod provides great damage, its mechanic makes it more of an assisting weapon. Also note that if you cannot afford the vast amounts of Greater Mana Potion that is required for sustaining your mana, you may also arguably swap the Avenger Emblem/Mechanical Glove for Magic Cuffs.
 * Armor: Spectre armor
 * Weapons: Nimbus Rod, Heat Ray, Inferno Fork, Bat Scepter, Razorpine, Blizzard Staff
 * Accessories: Destroyer Emblem, Sorcerer Emblem, Avenger Emblem/Mechanical Glove, Celestial Stone, Star Veil

For a good way to take on the Frost Moon as a mage, see YouTube: "Terraria: Frost Moon Final Wave SOLO (Mage Loadout | Arena Download")

Ranged set: The ranged set is likely capable of lashing out the most damage. With the proper gear and a suitable positioning (to trigger/keep the armor's ability), chances are good the player can utterly destroy any incoming enemies near instantly. The ranged set does however not supply any sort of healing, and is thus dependent on the healing of a mage or possibly the protection of a tank. As such, the ranged set is unlikely to succeed in single-player and is mainly for multi.
 * Armor: Shroomite armor (with a helmet variant that benefits your weapon)
 * Weapons: Candy Corn Rifle, Rocket Launcher (using Rocket III for ammo), Stynger, Snowman Cannon
 * Accessories: Destroyer Emblem, Ranger Emblem, Avenger Emblem/Mechanical Glove, Celestial Stone, Star Veil

Melee damage set: For soloing purposes, there appears to be two approaches with a melee damage set:
 * Armor: Chlorophyte Mask (head), Turtle Scale Mail (chest), Hallowed Greaves (legs) (These items are chosen purely on trying to maximize +% damage. They may not actually be the best items for generating melee damage.)
 * Weapons: Vampire Knives, The Horseman's Blade
 * Destroyer Emblem, Warrior Emblem, Fire Gauntlet, Celestial Stone, Star Veil
 * Vampire Knives: This method aims to sustain the player's life through the Vampire Knives. Though it is weaker than the mage set it is powerful enough (much due to the high armor) to survive several waves of the Pumpkin Moon and Frost Moon events, and can thus be used as a stepping stone to obtain weapons for other sets (such as Razorpine or the Blizzard Staff).

The melee damage set does not have much appeal in multi-player. The Vampire Knives do not heal allies and both its and the The Horseman's Blade's damage are likely to be outdone by that of the ranged and mage sets. At best it may offer some entertainment as another way of dealing damage. In this case the set may also benefit from weapons such as the Christmas Tree Sword and North Pole - given the player is healed by a mage.
 * The Horseman's Blade: This method relies of the The Horseman's Blade's ability to spawn homing pumpkins. It is dependent on a cluster of statues to spawn weak monsters, much like an ordinary statue farm. See YouTube: Terraria - Frost Moon Event Melee (Wave 15) for a video of this method.

Tanking set: The tanking set is, like the ranged set, aimed at multi-player. Its purpose is to direct monsters' attention so that more fragile characters can butcher them all. For this reason the set has a high value of defense, and consequently lesser damage than the other sets. If, during multi-player, the overall healing is good enough, some defense-granting accessories may arguably be replaced by damaging-increasing ones, such as those used by the melee-damage set. The weapon can similarly be something else than the Vampire Knives. Though the player probably won't die that often, this set is unlikely to perform well in single-player due to how the low damage won't allow for much wave advancement.
 * Armor: Turtle armor
 * Weapons: Vampire Knives
 * Accessories: Paladin's Shield, Frozen Turtle Shell, Star Veil, Celestial Stone, Star Veil

Notes: ¹ These items increase monster spawn. This will allow for more killing, which improves wave advancement.
 * All players should buff themselves during the fight. Suggested items to buff with are:
 * Potions: Any Well Fed-item, Battle Potion¹, Ironskin Potion, Regeneration Potion, Swiftness Potion, Thorns Potion, Shine Potion², Night Owl Potion², Hunter Potion²
 * Melee: Ale, any Flask (preferably Ichor), Obsidian Skin Potion (melee players are likely to touch the lava)
 * Ranged: Archery Potion (only if the player uses a bow or repeater)
 * Mage: Magic Power Potion, Mana Regeneration Potion
 * Stationary: Campfire, Heart Lantern, Water Candle¹, Crystal Ball (for mages), Honey³
 * Other: Wisp in a Bottle², Fairy Bell²

 ² These items help you see monsters, but can likely be omitted without much consequence.

³ As the honey buff is obtained by touching honey, its uptime may be tricky to maintain.
 * In addition to buff potions, players should also bring Greater Healing Potions and Greater Mana Potions. As the latter is likely to be consumed in extreme quantity, the player should bring vast amounts.
 * Please note that all the mentioned accessories above are recommended to have good modifiers, if not the best.
 * The mage, ranged, and melee damage sets should have Menacing (4%+ damage) or Lucky (4%+ critical strike chance) and the tanking set should have Warding (4+ Defense).
 * The Star Veil's (and the Cross Necklace's) ability to increase the player's invincibility after taking damage is crucial to this fight. Without it, the player is unlikely to survive past wave 13-14.
 * A Wings accessory is not mandatory, but can be of help. They will not see much use until Ice Queen shows up, at which point they can be used for chasing her and dodging her attacks. If used, it is recommended to acquire wings with as much fly time as possible, this currently being the Spooky Wings, Festive Wings and Tattered Fairy Wings.
 * The Vampire Knives will not work on targets under constant damage, such as when standing in lava or below a Nimbus Rod-cloud. A way to solve this is by making an arena in which the player is partly surrounded by a large rectangle of blocks. The Everscreams and Santa-NK1s will be able to pass through the wall and rise to the "floor" of it, (thus getting above the lava) at which point the Knives can hurt them, while the other monsters are kept outside/below the rectangle and have to remain in the lava.

Enemies in and points required to reach each wave:

Total points required to reach Wave 20: 10,160

Points Awarded for Defeating Enemies

 * Zombie Elf: 1
 * Gingerbread Man 1
 * Elf Archer: 2
 * Nutcracker: 4
 * Flocko: 4
 * Elf Copter: 6
 * Krampus: 8
 * Present Mimic: 10
 * Yeti: 16
 * Everscream: 40
 * Santa-NK1: 80
 * Ice Queen: 120