|Single Player Drops|
|600-1200 Snow Blocks||100%|
The Frost Legion is a Hardmode event during which unique Snowman enemies spawn and swarm a player's Town (or spawn point if nothing has been built yet), similar to the Goblin Army. The drops listed assume the player has at least 200 health.
Unlike the Goblin Army, the Frost Legion can only be initiated by the player, using the Snow Globe. The Legion will never invade on its own.
A world does not need to be in Hardmode in order to summon the Frost Legion, nor to acquire the Santa Claus NPC, however Hardmode is required in order to acquire the Snow Globe that summons it. Since the Frost Legion enemies are intended for Hardmode armor and weapons, it is not advisable for those without such gear to summon a Frost Legion.
 Initial event
When summoned, a message will appear: The Frost Legion is approaching from the [east/west]!
The direction specified in this message only pertains to the initial wave of Snowmen, which spawns at the World's edge and travels to the player's original spawn point. Additional waves spawn immediately within the player's original spawn area. If the message says "West", the Snowmen will come from the left. If the message says "East", they'll arrive from the right. Note that these directions are not related to the apparent motion of the Sun and the Moon, which, in Terraria, appear to move from left ("West") to right ("East").
When the Frost Legion is about to begin spawning around the player's spawn point, the following message appears: The Frost Legion has arrived! and the theme music will switch to the "Boss 3" theme.
 Completing the event
The event is completed when all the Snowmen in the legion are defeated. There will be 80 Snowmen, plus an additional 40 for each player that has a maximum health of 200 or more. In single player, the army will consist of 120 Snowmen, while in an 8-player game, with each player having 200 HP or more, it will spawn 400 Snowmen. With the maximum of 255 players above 200 health, the maximum number of snowmen in an invasion is 10,280.
When the final wave of Snowmen is on the screen, a message will appear saying, "The Frost Legion has been defeated!", and the theme music will return to normal.
- Snowmen override the current biome's enemies in the same way as Meteor Heads and the Goblin Army.
- The invasion will not prevent most other events, so you may end up fighting the Frost Legion and a boss at the same time. A Blood Moon may occur during a Frost Legion event, but will only cause other enemies to spawn after the Frost Legion has been defeated.
- If you happen to be on the Ocean floor when a Frost Legion is approaching, the initial wave of Snowmen will spawn underwater. Additional waves will only spawn when you return to the World spawn point.
- You do not need to be in the Snow Biome for the Frost Legion to spawn.
- Snowmen will not break down Doors unlike the Goblin Army which does.
- The Frost Legion and Snow Globes are often banned in multiplayer, because of the ability for Snow Balla's Snowballs to ruin houses.
- The Frost Legion does not leave if you exit the world and come back; they will stay until defeated.
- Due to the introduction of the Frost Moon, presents are now obtainable where it is not in the Christmas season, therefore snow globes are obtainable when it is not Christmas and the Frost legion can be summoned
- Whenever you defeat the Frost Legion for the first time, the clothier will sell the Balla Hat and the Gangsta Hat for free.
- As in other invasions, if you're far enough underground, the snowmen won't spawn, even after getting the message that they've arrived. This means you don't have to head back to your house immediately upon receiving message of an imminent attack. However, the invasion will remain and the snowmen will appear if you surface.
- The Snowmen are incapable of jumping down from simple wooden platforms, meaning it is possible to construct a basic trench with a wooden platform above it, and be completely out of harms way.
- A fourth Snowman sprite is available in the game resources, with dynamite lodged in its head. It is not used in the game, likely for the damage to blocks that it would cause. It might also not be included because it might demolish or trap its own allies.
- 1.1.1: Introduced.