Deerclops

The Deerclops is a pre-Hardmode boss. It is one of the final bosses a player may encounter during pre-Hardmode. It can be summoned manually using a Deer Thing at any time of day in the snow biome.

While the Deerclops is alive, its exclusive music Deerclops will play. When Otherworldly music is enabled, the track Boss 1 (Otherworldly) will play instead.

Has 21000 Health and 60 Attack in Master Mode

Spawn
The Deerclops can be summoned using a Deer Thing at any time of day as long as the player is in the snow biome. Although it can be summoned immediately, the Deer Thing requires either Demonite or Crimtane ore to craft which isn't readily available until after the Eye of Cthulu has been defeated.