- See also: Guide:Defending against events
The Frost Moon is an endgame Christmas-themed event summoned with the Naughty Present at night, and ending at dawn (4:30AM). It can be summoned any time of year, and does not require the actual Christmas season. During the event, unique and highly difficult enemies spawn at high rates and attack the player. It is similar to the Pumpkin Moon event, but more difficult, and is currently the most difficult event in the game. Visually, the moon turns into a snowman head, though remaining in its current phase. Unique music also plays.
The entire event consists of 15 waves, plus 5 "bonus waves". Waves progress as you reach certain kill scores (though kill scores are not displayed to the player). Each killed enemy increases the kill score by a differing amount. After a wave's required score is met, the next wave begins, and the kill score is reset to 0. Chat messages will indicate when the wave has advanced, and which wave has been achieved. See the table below (Waves) for the points awarded for each enemy and the score required for each wave.
The Naughty Present that summons the Frost Moon requires materials only available in Hardmode worlds where the player has already defeated Plantera. As such, it is intended to present a challenge even to players with the best possible equipment. In the final waves, multiple boss-level enemies are fought at once.
Frost Moon enemies drop powerful weapons, as well as pet and vanity items. Most drop with extreme rarity, and even players who manage to complete the event will find they need to do so several times before obtaining them. Drop chances for Boss-dropped items increase the later the wave in which they spawn. At 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.
From Zombie Elf:
From Ice Queen:
 Points per kill
- 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
 Wave scores & enemies
- Total points required to reach Wave 20: 10,160
- Water Candles, Battle Potions and Calming Potions have no effect during the invasion.
- If the player is killed during the event, the event is not cancelled. The player will keep re-spawning and can continue fighting its enemies as the event continues until dawn. In single-player games, exiting the world and reloading it will cancel the event.
- The Frost Moon does not stack with the Blood Moon. Summoning the Frost Moon will cancel the Blood Moon if it is active.
- Spawn rates for areas where Frost Moon enemies cannot spawn are also increased. For example, there will spawn lots of Sharks and Crabs in the Ocean, allowing the player to farm for Pirate Maps.
- The event can be triggered in pre-Hardmode worlds if its summoning item is brought there.
- Made it slightly easier to advance in frostmoon waves.
- Made several frostmoon monsters shoot slower and do less damage.
- Pumpkin Moon and Frost Moon can now be started when using a Snowman pet.
- All waves in Frost Moon correctly use "Flocko" in the warning.
- Flocko & Elf Copter now both correctly run away at dawn.
- Fixed frost moon wave display test (Elf Zombie to Zombie Elf).
- 1.2.2: Introduced.
| Game mechanics|
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