Here is the full list of all 20 Savage Lands achievements.
Kill 1 Forest Giant.
Kill 10 Undead Furies.
Kill 3 Plague Wolves.
Kill 5 Wolves.
Build a Blacksmith structure.
Kill 25 creatures.
Kill 5 Deer.
Complete all Day 1 Tasks.
Kill 5 Skeletons.
Chop down 10 trees.
Mine 25 items from any rock.
Build a Leanto.
Kill 1 creature.
Build your first campfire.
Craft your first weapon.
Join any Hostile or Friendly Server.
Build a Wooden Shack.
Craft a compass.