This achievement requires you to complete the Pirate Playground level.
All you need to do is complete the first 3 quests on the Pirate Playground level
. One asks you to spawn in some pigs/chickens.
Use the discovery tool to discover a pig and a chicken hanging around on the world, then use it to spawn in as many pigs/chickens as the quest requires.One asks you to clear some thorns and open a chest.
Use the discovery tool to remove the thorns and then open the chest.One asks you to spawn in a pirate throne.
Go to the thorny treasure chest spot and around the chest is a pirate throne. Use the discovery tool to discover it then go back to the guy and spawn it back in.
(if you're finding it difficult to find the quests, look on the minimap for golden brick icons)This will also net you the "Rank - Discoverer Builder!" achievement.Good luck and enjoy LEGO Worlds!